Page 1

                             UNITED STATES
                  SECURITIES AND EXCHANGE COMMISSION
                        Washington, D.C. 20549

                              Form 11-K

(Mark One)

[X]	ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES
	EXCHANGE ACT OF 1934

	For the fiscal year ended December 31, 2006

OR

[ ]	TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE
	SECURITIES EXCHANGE ACT OF 1934

	For the transition period from _______________ to _______________

	Commission file number 001-9383

       A. Full title of the plan and the address of the plan, if
          different from that of the issuer named below:

    	         WESTAMERICA BANCORPORATION TAX DEFERRED
                     SAVINGS/RETIREMENT PLAN (ESOP)

       B. Name of issuer of the securities held pursuant to the plan and
          the address of its principal executive office:

	              Westamerica Bancorporation
	 	             1108 Fifth Avenue
		       San Rafael, California 94901



Page 2

                    WESTAMERICA BANCORPORATION

              TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)


                        FINANCIAL STATEMENTS

                AS OF DECEMBER 31, 2006 AND 2005 AND

        FOR THE YEARS ENDED DECEMBER 31, 2006, 2005 AND 2004

                                AND

                       SUPPLEMENTAL SCHEDULES

             AS OF AND FOR THE YEAR ENDED DECEMBER 31, 2006

                                AND

                  REPORT OF INDEPENDENT REGISTERED

                     PUBLIC ACCOUNTING FIRM



Page 3

                      WESTAMERICA BANCORPORATION
              TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)

                       FINANCIAL STATEMENTS
                    AND SUPPLEMENTAL SCHEDULES


                         TABLE OF CONTENTS


                                                                      Page
                                                                      ----
Report of Independent Registered Public Accounting Firm                 4

Financial Statements:

   Statement of Net Assets Available for Plan Benefits as of
      December 31, 2006 and 2005                                        5

   Statement of Changes in Net Assets Available for Benefits
      for the years ended December 31, 2006, 2005 and 2004              6

   Notes to Financial Statements                                     7-15

Supplemental Schedules:

   Schedule H, Line 4i - Schedule of Asserts (Held at End of Year)
      As of December 31, 2006                                       16-17

   Schedule H, Line 4j - Schedule of Reportable Transactions
      for the year ended December 31, 2006                             18

Signatures                                                             19

Exhibit Index                                                          20




Page 4


             REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


To the Employee Benefits and
   Compensation Committee of the
   Board of Directors of
   Westamerica Bancorporation

We have audited the accompanying statement of net assets available for benefits
of the Westamerica Bancorporation Tax Deferred Savings/Retirement Plan (ESOP)
(the "Plan") as of December 31, 2006 and 2005, and the related statement of
changes in net assets available for benefits for the years ended December 31,
2006, 2005 and 2004.  These financial statements are the responsibility of the
Plan's management.  Our responsibility is to express an opinion on these
financial statements based on our audits.

We conducted our audits in accordance with the auditing standards of the Public
Company Accounting Oversight Board (United States).  Those standards require
that we plan and perform the audits to obtain reasonable assurance about whether
the financial statements are free of material misstatement.  An audit includes
examining, on a test basis, evidence supporting the amounts and disclosures in
the financial statements.  An audit also includes assessing the accounting
principles used and significant estimates made by management, as well as
evaluating the overall financial statement presentation.  We believe
that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in
all material respects, the net assets available for benefits of the Westamerica
Bancorporation Tax Deferred Savings/Retirement Plan (ESOP) as of December 31,
2006 and 2005, and the changes in net assets available for benefits for the
years ended December 31, 2006, 2005 and 2004, in conformity with accounting
principles generally accepted in the United States of America.

Our audits were made for the purpose of forming an opinion on the basic
financial statements taken as a whole.  The supplemental schedules of assets
(held at end of year) and reportable transactions, as of and for the year ended
December 31, 2006, are presented for the purpose of additional analysis and are
not a required part of the basic financial statements, but are supplementary
information required by the United States Department of Labor Rules and
Regulations for Reporting and Disclosure under the Employee Retirement
Income Security Act of 1974.  These supplemental schedules are the
responsibility of the Plan's management.  The supplemental schedules have been
subjected to the auditing procedures applied in the audit of the basic 2006
financial statements and, in our opinion, are fairly stated in all material
respects in relation to the basic 2006 financial statements taken as a whole.


                                               /s/ Perry-Smith LLP
                                               -------------------

Sacramento, California
June 26, 2007



Page 5

                         WESTAMERICA BANCORPORATION
                 TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)

            STATEMENT OF NET ASSETS AVAILABLE FOR PLAN BENEFITS

              For the Years Ended December 31, 2006 and 2005




                                                        2006        2005
                                                     ----------------------
   ASSETS
                                                          
Investments (Notes 3 and 4)                         $54,952,663 $56,211,752
                                                     ----------------------

Receivables:
   Employer contributions                                 --         62,888
   Participant contributions                              --         84,719
   Interest                                               --            109
                                                     ----------------------
      Total receivables                                   --        147,716
                                                     ----------------------
      Total assets                                   54,952,663  56,359,468
                                                     ----------------------

   LIABILITIES

Accrued trustee fees                                     11,400      12,577
                                                     ----------------------
Net assets available for benefits                   $54,941,263 $56,346,891
                                                     =========== ===========


The accompanying notes are an integral
part of these financial statements.





Page 6

                      WESTAMERICA BANCORPORATION
                TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)

      STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR PLAN BENEFITS

          For the Years Ended December 31, 2006, 2005 and 2004




                                            2006        2005        2004
                                        -----------------------------------
   ADDITIONS
                                                       
Investment income:
   Net  appreciation (depreciation) in
    fair value of investments (Note 3) $    262,793 $(2,948,412)$ 7,418,432
   Dividends                              1,548,212   1,321,171   1,105,556
   Interest on participant loans             71,353      57,540      61,938
                                        -----------------------------------
      Total investment  income (loss)     1,882,358  (1,569,701)  8,585,926
                                        -----------------------------------

Contributions:
   Participants                           2,064,360   2,338,918   2,313,392
   Employer                               1,284,649   1,509,026   1,508,125
   Participant rollovers                    437,189     118,533     225,627
                                        -----------------------------------
      Total contributions                 3,786,198   3,966,477   4,047,144
                                        -----------------------------------
      Total additions                     5,668,556   2,396,776  12,633,070
                                        -----------------------------------

   DEDUCTIONS


Benefits paid to participants             7,044,524   7,738,145   4,353,746
Administrative expenses (Note 6)             29,660      49,324      51,327
                                        -----------------------------------
      Total deductions                    7,074,184   7,787,469   4,405,073
                                        -----------------------------------
      Net (decrease) increase            (1,405,628) (5,390,693)  8,227,997


Net assets available for benefits:
   Beginning of year                     56,346,891  61,737,584  53,509,587
                                        -----------------------------------
   End of year                         $ 54,941,263 $56,346,891 $61,737,584
                                        ===========  =========== ===========



                   The accompanying notes are an integral
                   part of these financial statements.


Page 7

                          WESTAMERICA BANCORPORATION
                   TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)

                         NOTES TO FINANCIAL STATEMENTS


1. DESCRIPTION OF PLAN

The following description of the Westamerica Bancorporation (the "Company") Tax
Deferred Savings/Retirement Plan (ESOP) (the "Plan") provides only general
information.  Participants should refer to the Summary Plan Description and Plan
Document for a more complete description of the Plan's provisions.

General
-------

The Plan is a defined contribution plan covering substantially all employees of
the Company.  The Plan, which became effective October 1, 1985, is intended to
be a qualified stock bonus plan under section 401(a) of the Internal Revenue
Code ("IRC") and is designated as an employee stock ownership plan or ESOP.
Portions of the Plan are also intended to qualify as a qualified cash or
deferred arrangement within the meaning of section 401(k) of the IRC.  Effective
April 1, 2006, the Plan was amended and restated to provide for Roth elective
contributions.

The Employee Benefits and Compensation Committee of the Company's Board of
Directors (the "Committee") delegates the administration of the Plan to the
Company's Pension Management Committee.  The Committee has the responsibility
for the general operation of the Plan, including the resolution of any questions
arising under the Plan agreement.  The Plan is subject to the provisions of the
Employee Retirement Income Security Act of 1974 (ERISA).  Investments in the
Plan are participant directed, with the exception of employer contributions
which are invested in shares of the Company's common stock at the time of
contribution. Subsequent to investment in the Company's common stock,
participants may direct employer matching contributions among all investment
options.  Vanguard Fiduciary Trust Company serves as Trustee of the Plan.

During 2005, Redwood Empire Bancorp (Redwood) was merged into Westamerica
Bancorporation.  The Plan was amended in order for former employees of Redwood's
wholly-owned subsidiary, National Bank of the Redwoods, to be credited with
their prior service for eligibility in the Plan.

Eligibility
-----------

Under the Plan, employees of the Company who are compensated on a salaried basis
become eligible to participate in the plan on the first day of the calendar
month coinciding with or following the date the employee completes 90
consecutive days of service with the Company or completes 1,000 service hours in
a 12-month consecutive period.

Vesting
-------

Participants are immediately vested in their salary-deferral contributions, the
Company's discretionary and matching contributions, plus actual earnings
thereon.


Page 8

1.	DESCRIPTION OF PLAN (Continued)

Contributions
-------------

Each year, participants may make salary deferral contributions in any whole
percentage of pretax annual compensation subject to certain IRC limitations.
Effective April 1, 2006, participants may also elect to make salary deferral
contributions on an after-tax basis in whole percentage increments, subject to
certain limitations defined by the Plan.  These contributions are designated as
Roth elective contributions.

The Company makes a matching contribution equal to 100 percent of the
participant's elective contribution and Roth elective contribution, up to a
maximum of 6 percent of the participant's compensation.  Additional amounts may
be contributed at the discretion of the Company's Board of Directors.
Participants may also contribute amounts representing distributions from other
qualified Roth accounts, defined benefit, or contribution plans.  For the years
ended December 31, 2006, 2005 and 2004, the Company made no discretionary
contributions.  Company contributions are subject to certain IRC limitations.

Participant Accounts
--------------------

Individual accounts are maintained for each Plan participant.  Each
participant's account is credited with the participant's contribution,
allocation of the Company's matching and discretionary contributions, allocation
of Plan earnings, and charged with withdrawals, allocations of Plan losses and
administrative expenses.

Employer matching contributions are allocated to participants based on the
Participant's elective contribution.  Employer discretionary contributions are
allocated to the account of each participant in ratio of the participant's
eligible compensation to the total eligible compensation for all Plan
participants.

Participants' Investment Options
--------------------------------

Company matching contributions are invested in the Westamerica Common Stock
Fund in accordance with the Plan Document.  Participants may redirect Company
matching contributions from the Westamerica Common Stock Fund to other
investment options at their discretion.

Participants direct participant contributions in whole or in part in any of the
following investment fund options as of December 31, 2006:

*   The Westamerica Common Stock Fund, which is invested in the Company's
common stock and temporary interest-bearing money market funds.

*   Vanguard 500 Index Fund, which invests in the 500 stocks that make up the
unmanaged Standard & Poor's 500 Composite Stock Price Index, a widely
recognized benchmark of U.S. stock market performance.


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1.	DESCRIPTION OF PLAN (Continued)

Participants' Investment Options (Continued)
--------------------------------

*   Vanguard Explorer Fund, which invests in a diversified group of small-
company stocks with prospects for above-average growth.  The fund may
invest up to 20% in foreign securities and up to 15% in restricted or illiquid
securities.

*   Vanguard Morgan Growth Fund, which invests primarily in stocks of large
and mid-sized companies that have strong records of growth in sales and earnings
or that have performed well during certain market cycles.

*   Vanguard Prime Money Market Fund, which invests in short-term, high-
quality money market instruments issued by financial institutions, nonfinancial
corporations, the U.S. government, and federal agencies.

*   Vanguard Total Bond Market Index Fund, which invests in bonds that attempt
to match the performance of the unmanaged Lehman Brothers Aggregate
Bond Index, which is a widely recognized measure of the taxable U.S. bond
market.

*   Vanguard Total International Stock Index Fund, which invests in three
Vanguard international index funds: a European fund, a Pacific fund, and an
emerging markets fund.  These funds invest in the stock of companies in more
than 30 countries.

*   Vanguard Windsor II Fund, which invests in a diversified group of out-of-
favor stocks of large capitalization companies.  The stocks selected generally
sell at prices below the market average compared to their dividend income and
future return potential.

*   Vanguard Extended Market Index Fund, which invests in a broadly
diversified portfolio of stocks of small and medium sized companies that are
regularly traded on the New York and American Stock Exchanges and NASDAQ over-
the-counter market.  The portfolio is designed to be representative of the
Wilshire 4500 Index.

*   Vanguard Short-Term Federal Fund, which invests primarily in short-term
securities issued by U.S. government agencies, but may also invest in U.S.
Treasury securities and in repurchase agreements backed by U.S. Treasury or
federal agency securities.  To reduce fluctuations in its share price, the fund
maintains an average maturity of 1 to 3 years.

*   Vanguard Target Retirement Income Fund, which invests in other Vanguard
mutual funds according to an asset allocation designed for investors currently
in retirement.  It typically allocates 70% of assets to bonds and 30% to stocks.

*   Vanguard Target Retirement 2005, which is invested in other Vanguard
mutual funds.  It typically allocates 50% of assets to bonds and 50% to stocks.


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1.	DESCRIPTION OF PLAN (Continued)

Participants' Investment Options (Continued)
--------------------------------

*   Vanguard Target Retirement 2010, which is invested in other Vanguard
mutual funds.  It typically allocates 57% of assets to stock, 41% to bonds and
2% to stable value funds.

*   Vanguard Target Retirement 2015, which is invested in other Vanguard
mutual funds according to an asset allocation designed for investors currently
in retirement.  It typically allocates 67% of assets to stocks and 33% to bonds.

*   Vanguard Target Retirement 2025, which is invested in other Vanguard
mutual funds.  It typically allocates 82.5% of assets to stocks and 17.5% to
bonds.

*   Vanguard Target Retirement 2035, which is invested in other Vanguard
mutual funds.  It typically allocates 90% of assets to stocks and 10% to bonds.

*   Vanguard Target Retirement 2040, which is invested in other Vanguard
mutual funds.  Typically allocates 90% of assets to stock and 10% to bonds.

*   Vanguard Target Retirement 2045, which is invested in other Vanguard
mutual funds.  It typically allocates 90% of assets to stocks and 10% to bonds.

*   Vanguard Target Retirement 2050, which is invested in other Vanguard
mutual funds.  It typically allocates 90% of its assets to stocks and 10% to
bonds.

Participants may change their investment options at any time directly through
The Vanguard Group.

Participant Loans
-----------------

Participants may borrow a minimum of $1,000 up to a maximum equal to the lesser
of 50 percent of their account balance, 100 percent of participant
contributions, or $50,000.  For the purposes of this limit, all qualified plans
of the Company shall be considered one plan. Loans are secured by the balance in
the participant's account.  Participant loans are funded by selling investments
in the borrowing participant's accounts and bear interest at prevailing market
rates at the time the funds are borrowed. Loan terms range from 1 to 5 years.
Principal and interest is paid ratably through payroll deductions and invested
in the borrowing participant's accounts in accordance with their investment
directions.


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1.	DESCRIPTION OF PLAN (Continued)

Payment of Benefits
-------------------

Upon termination of service for any reason, a participant may elect to receive a
lump-sum distribution equal to the value in his or her account.  Distributions
for the value of a participant's account invested in the Westamerica Common
Stock Fund stock are made in the form of the Company's common stock plus cash
for any fractional shares or, if a participant elects, in cash or an in-kind
transfer, as provided by the Plan document.  Participants may also receive in-
service distributions on account of hardship or after attaining age 59 1/2.
Cash dividends paid on Westamerica Bancorporation common stock allocated to
participant accounts may be paid to participants in cash or be credited to the
participant's account as earnings.  If the value of a separated participant's
benefit is not more than $1,000, the benefit shall be automatically paid in a
single lump sum in cash or, if elected, directly to an eligible retirement plan.
Benefits payable to participants for amounts greater than $1,000 may be made in
cash or other form of distribution, as defined by the Plan.  As of December 31,
2006 and 2005, there were no benefits payable to participants that have elected
to withdraw from the Plan but have not yet been paid.

Voting Rights
-------------

Each participant is entitled to exercise voting rights attributable to the
Westamerica Bancorporation common stock shares allocated to his or her account
and is notified by the Trustee prior to the time that such rights are to be
exercised.  The Trustee is not permitted to vote any allocated share for which
instructions have not been given by a participant.

Plan Termination
----------------

Although it has not expressed any interest to do so, the Company has the right
under the Plan to discontinue its contributions at any time and to terminate the
Plan, subject to the provisions of ERISA.

Administrative Expenses
-----------------------

The Company provides bookkeeping and other administrative services for the Plan
at no charge.  The Company pays the Plan's annual account maintenance fees for
participants actively employed by the Company and other administrative expenses.

2.	SUMMARY OF ACCOUNTING POLICIES

Basis of Accounting
-------------------

The financial statements of the Plan have been prepared in accordance with
accounting principles generally accepted in the United States of America.


Page 12

2.	SUMMARY OF ACCOUNTING POLICIES (Continued)

Use of Estimates
----------------

The preparation of financial statements in conformity with accounting principles
generally accepted in the United States of America requires the Plan's
management to make estimates and assumptions that affect the reported amounts of
net assets available for benefits and changes therein and disclosure of
contingent assets and liabilities.  Actual results could differ from those
estimates.  The Plan utilizes various investment instruments, including the
common stock of the Company and mutual funds.  Investment securities, in
general, are exposed to various risks, such as interest rate, credit, currency
and overall market volatility.  Due to the level of risk associated with certain
investment securities, it is reasonably possible that changes in the values of
investment securities will occur in the near term and that such changes could
materially affect the amounts reported in the financial statements.

Concentrations of Investments
-----------------------------

Included in investments at December 31, 2006 and 2005 are shares of the
Westamerica Common Stock Fund amounting to $29,608,768 and $34,398,813,
respectively.  The Westamerica Common Stock Fund represents 54% and 61% of total
investments at December 31, 2006 and 2005, respectively.  A significant decline
in the market value of the Company's stock would have a materially adverse
effect on the Plan's net assets available for benefits.

Investment Valuation and Income Recognition
-------------------------------------------

The Plan's investments are stated at fair value.  Shares of registered
investment companies (mutual funds) are reported at fair value based on the
quoted market price of the fund, which represents the net asset value of shares
held by the Plan at year end.  The Company's common stock is valued at its
quoted market price.  Participant loans are valued at their outstanding loan
balances.

Purchases and sales of securities are recorded on a trade-date basis.  Interest
income is recorded on the accrual basis.  Dividends are recorded on the ex-
dividend date.  Net appreciation (depreciation) in fair value of investments
includes net unrealized market appreciation (depreciation) of investments and
net realized gains and losses on the sale of investments during the period.

Management fees and operating expenses charged to the Plan for investments in
shares of registered investment companies (mutual funds) are deducted from
income earned on a daily basis and are not separately reflected.  Consequently,
management fees and operating expenses are reflected as a reduction of
investment return for such investments.  Trustee fees for Westamerica
Bancorporation common stock are charged to the Westamerica Common Stock Fund.

Payment of Benefits
-------------------

Benefits are recorded when paid.


Page 13

2.	SUMMARY OF ACCOUNTING POLICIES (Continued)

Reclassifications
-----------------

Certain amounts shown in the prior year have been reclassified to conform to the
current year presentation.

Impact of New Financial Accounting Standards
--------------------------------------------

Fair Value Measurements

In September 2006, the Financial Accounting Standards Board (FASB) issued
Statement No. 157 (SFAS 157), Fair Value Measurements.  SFAS 157 defines fair
value, establishes a framework for measuring fair value and expands disclosures
about fair value measurements.  SFAS 157 applies whenever other standards
require (or permit) assets or liabilities to be measured at fair value but does
not expand the use of fair value in any new circumstances.  In this standard,
the FASB clarifies the principle that fair value should be based on the
assumptions market participants would use when pricing the asset or liability.
In support of this principle, SFAS 157 establishes a fair value hierarchy that
prioritizes the information used to develop those assumptions. The provisions of
SFAS 157 are effective for financial statements issued for fiscal years
beginning after November 15, 2007 and interim periods within those fiscal years.
The provisions should be applied prospectively, except for certain specifically
identified financial instruments.  Management does not expect the adoption of
SFAS 157 to have a material impact to the Plan's financial position or results
of operations.

Fair Value Accounting

In February 2007, the FASB issued SFAS No. 159, The Fair Value Option for
Financial Assets and Financial Liabilities - Including an Amendment of FASB
Statement No. 115 (SFAS 159).  This Statement permits entities to choose to
measure many financial instruments and certain other items at fair value.
Unrealized gains and losses on items for which the fair value option has been
elected will be reported in earnings.  The objective is to improve financial
reporting by providing entities with the opportunity to mitigate volatility in
reported earnings caused by measuring related assets and liabilities differently
without having to apply complex hedge accounting provisions.  This Statement is
expected to expand the use of fair value measurement, which is consistent with
the FASB's long-term measurement objectives for accounting for financial
instruments.  SFAS 159 is effective for fiscal years beginning after November
15, 2007.  Early adoption is permitted as of the beginning of the previous
fiscal year provided that the entity makes that choice in the first 120 days of
that fiscal year and also elects to apply the provisions of SFAS 157.
Management has not chosen early adoption of SFAS 159. Management is in the
process of evaluating the impact the adoption of SFAS 159 will have on the
Plan's financial position and results of operations.


Page 14

3.   INVESTMENTS

    The Plan's investments, including investments bought, sold, and held
    during the year, appreciated in value by $262,793 and $7,418,432
    during 2006 and 2004, respectively, and depreciated in value by
    $2,948,412 during 2005, as follows:

    
    

                                       2006        2005        2004
                                    -----------------------------------
                                                  
    Westamerica Common Stock Fund  $(1,609,963)$(3,680,251)$ 6,047,876
    Mutual funds                     1,872,756     731,839   1,370,556
                                    -----------------------------------
                                   $   262,793 $(2,948,412)$ 7,418,432
                                    =========== =========== ===========
    

    The following table presents investments at fair value that represent
    5% or more of the Plan's net assets as of December 31, 2006 and 2005:

    
    

                                                   2006        2005
                                                -----------------------
                                                     
    Westamerica Common Stock Fund              $29,608,768 $34,398,813
    Vanguard 500 Index Fund                      5,335,868   4,584,551
    Vanguard Prime Money Market Fund             3,495,303   2,851,975
    Vanguard Target Retirement 2015 Fund         2,932,013   2,473,170
    Vanguard Morgan Growth Fund                  2,918,998   2,864,909
    Other Investments                           10,661,713   9,038,334
                                                -----------------------
                                               $54,952,663 $56,211,752
                                                =========== ===========
    


4.   INVESTMENT IN WESTAMERICA BANCORPORATION COMMON STOCK

    The Plan's investments at December 31, 2006 and 2005 in Westamerica
    Bancorporation common stock are as follows:

    
    

                                                   2006        2005
                                                -----------------------
                                                     

         Number of shares                          584,806     647,941
                                                =========== ===========
         Cost                                  $16,062,287 $17,211,268
                                                =========== ===========
         Fair value                            $29,608,768 $34,398,813
                                                =========== ===========
    


Page 15

5.	FEDERAL INCOME TAX STATUS

The Internal Revenue Service has determined and informed the Company by a letter
dated December 12, 2001, that the Plan is qualified and the trust established
under the Plan is tax-exempt, under the appropriate sections of the Internal
Revenue Code. The Plan has  been amended since receiving the determination
letter; however, the Plan's management and the Plan's tax counsel believe that
the Plan currently is designed and being operated in compliance with the
applicable requirements of the Internal Revenue Code and the Plan continues to
be tax exempt.  Therefore, no provision for income taxes has been included in
the Plan's financial statements.

6.	RELATED PARTY TRANSACTIONS

Plan investments include shares of mutual funds, including the Westamerica
Common Stock Fund which invests in the common stock of the Company, managed
by an affiliate of Vanguard Fiduciary Trust Company (VFTC).  VFTC is the Trustee
as defined by the Plan and, therefore, these transactions qualify as party-in-
interest transactions.  Fees paid by the Plan for investment management services
were included as a reduction of the return earned on each fund.  Fees paid by
the Plan for trustee services in connection with the Westamerica Common Stock
Fund for the years ended December 31, 2006, 2005 and 2004 amounted to $45,837,
$49,324 and $51,327, respectively.

7.	RECONCILIATION OF FINANCIAL STATEMENTS TO FORM 5500




The following is a reconciliation of net assets available for benefits per the
financial statements at December 31, 2006 to Form 5500:

                                                              
Net assets available for benefits per the financial statements   $  54,941,263
Addition:
  Accrued expenses                                                      11,400
                                                                 -------------
Net assets available for benefits per Form 5500                  $  54,952,663
                                                                 =============

The following is a reconciliation of administrative expenses per the financial
statements for the year ended December 31, 2006 to Form 5500:

Administrative expenses per the financial statements             $      29,660
Less:
  Accrual of administrative expenses                                   (11,400)
                                                                 -------------
Administrative expenses	per Form 5500                            $      18,260
                                                                 =============




8.	PLAN AMENDMENTS

Effective April 2006, the Plan was amended and restated to provide participants
with the option of making salary deferral contributions to the Plan on an after-
tax basis (Roth elective contributions).  In addition, the Plan was amended to
provide for Company matching contributions on both participant elective and Roth
contributions.

Effective January 2006, the hardship withdrawal rules were also revised.


Page 16

                                  SUPPLEMENTAL SCHEDULES
                                  ----------------------


                                WESTAMERICA BANCORPORATION
                         TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)

                         EMPLOYER IDENTIFICATION NUMBER: 94-2156203
                                     PLAN NUMBER: 002

                SCHEDULE H, LINE 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR)

                                     December 31, 2006




                                              (c)
                  (b)               Description of Investment
          Identity of Issuer,       Including Maturity Date,                  (e)
            Borrower, Lessor        Rate of Interest, Collate    (d)        Current
(a)         or Similar Party         Par or Maturity Value      Cost         Value
--------------------------------------------------------------------------------------
                                                              
 *   Westamerica Common                   Common Stock
         Stock Fund                      584,806 shares     $16,062,287 $ 29,608,768

 *   Vanguard 500 Index Fund              Mutual Fund
                                         40,850 shares        4,557,122    5,335,868

 *   Vanguard Prime Money                 Mutual Fund
         Market Fund                    3,495,303 shares      3,495,303    3,495,303

 *   Vanguard Target Retirement           Mutual Fund
         2015 Fund                       401,914 shares       2,718,860    2,932,013

 *   Vanguard Morgan Growth               Mutual Fund
         Fund                            153,714 shares       2,637,280    2,918,998

 *   Vanguard Total International         Mutual Fund
         Stock Index Fund               1,079,879 shares      1,752,852    2,470,707

 *   Vanguard Windsor II Fund             Mutual Fund
                                         56,230 shares        1,702,583    1,954,077

 *   Vanguard Target Retirement           Mutual Fund
         2025 Fund                       85,598 shares        1,017,580    1,116,232

 *   Vanguard Total Bond Market           Mutual Fund
         Index Fund                      107,441 shares       1,078,856    1,073,344



Page 17

                                WESTAMERICA BANCORPORATION
                         TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)

                         EMPLOYER IDENTIFICATION NUMBER: 94-2156203
                                    PLAN NUMBER: 002

                SCHEDULE H, LINE 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR)
                                       (Continued)
                                    December 31, 2006

                                              (c)
                  (b)               Description of Investment
          Identity of Issuer,       Including Maturity Date,                  (e)
            Borrower, Lessor        Rate of Interest, Collate    (d)        Current
(a)         or Similar Party         Par or Maturity Value      Cost         Value
--------------------------------------------------------------------------------------

 *   Vanguard Extended Market             Mutual Fund
         Index Fund                      20,052 shares          644,611      775,655

 *   Vanguard Target Retirement           Mutual Fund
         2035 Fund                       32,299 shares          405,652      447,999

 *    Vanguard Target Retirement           Mutual Fund
         2005 Fund                       14,181 shares          411,376      429,738

 *   Vanguard Target Retirement           Mutual Fund
         2045 Fund                       24,872 shares          325,793      356,186

 *   Vanguard Explorer Fund               Mutual Fund
                                          4,714 shares          364,099      352,192

 *   Vanguard Target Retirement           Mutual Fund
         Income Fund                     27,985 shares          294,650      300,000

 *   Vanguard Short Term                  Mutual Fund
         Federal Fund                    12,995 shares          135,672      133,594

 *   Vanguard Target Retirement           Mutual Fund
         2010 Fund                        7,326 shares          123,815      135,645

 *   Vanguard Target Retirement           Mutual Fund
         2050 Fund                         39 shares                866          885

 *   Vanguard Target Retirement           Mutual Fund
         2040 Fund                         24 shares                541          548

     Participant loans              Interest rates ranging    1,114,911    1,114,911
                                    from 5.00% to 9.75%      -------------------------

                                                            $38,844,709 $ 54,952,663
                                                             ============ ============
* Party-in-interest to the Plan.



Page 18

                                      WESTAMERICA BANCORPORATION
                             TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)

                             EMPLOYER IDENTIFICATION NUMBER: 94-2156203
                                          PLAN NUMBER: 002

                      SCHEDULE H, LINE 4j - SCHEDULE OF REPORTABLE TRANSACTIONS

                                For the Year Ended December 31, 2006




                                                                                                (f)
                                                                               (e)         Current Value
     (a)                 (b)                        (c)            (d)      Historical      of Asset on     (g)
  Identity of        Description                  Purchase       Selling      Cost of      Transaction    Net Gain
Party Involved         of Asset                    Price          Price        Asset          Date        or (Loss)
-------------------------------------------------------------------------------------------------------------------
                                                                                      

Vanguard          Vanguard Prime Money Mkt Fund  $2,266,732                               $2,266,732
Vanguard          Vanguard Prime Money Mkt Fund                $1,623,404  $1,623,403      1,623,404   $     --
Vanguard          Westamerica Common Stock Fund   2,656,606                                2,656,606
Vanguard          Westamerica Common Stock Fund                 5,824,111   3,805,587      5,824,111    2,018,524





Page 19

                            Duly Authorized Signature

Pursuant to the requirements of the Securities Exchange Act of 1934, the
trustees (or the persons who administer the employee benefit plan) have duly
caused this annual report to be signed on its behalf by the undersigned hereunto
duly authorized.

WESTAMERICA BANCORPORATION
TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)


Date:      June 29, 2007
        ---------------------------

By:       /s/ John "Robert" Thorson
        ---------------------------
  John "Robert" Thorson
  Senior Vice President
  And Member, Pension Management Committee





Page 20

                         Exhibit Index


Exhibit
Number            Description
-------        --------------------------------------------------------
23 Consent of Independent Registered Public Accounting Firm
99 Certification pursuant to 18 U.S.C. Section 1350