Page 1

Registration No. 333-_______

                           SECURITIES AND EXCHANGE COMMISSION
                                WASHINGTON, D.C. 20549
                                     __________

                                      FORM S-8

                               REGISTRATION STATEMENT
                                        UNDER
                              THE SECURITIES ACT OF 1933
                                     __________

                            WESTAMERICA BANCORPORATION
                (Exact name of registrant as specified in its charter)


          California					    94-2156203
(State or other jurisdiction of                  (I.R.S. Employer
 incorporation or organization)	              entification No.)

            1108 Fifth Avenue
         San Rafael, California	                    94901
 (Address of Principal Executive Offices)             (Zip Code)

                            WESTAMERICA BANCORPORATION
                    TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)
                             (Full title of the plan)

                                   David L. Payne
                    Chairman, President and Chief Executive Officer
                              Westamerica Bancorporation
                                    1108 Fifth Avenue
                              San Rafael, California  94901
                        (Name and address of agent for service)

                                    (415) 257-8000
            (Telephone number, including area code, of agent for service)

                            CALCULATION OF REGISTRATION FEE
________________________________________________________________________________
    Title of                        Proposed          Proposed      Amount of
   Securities      Amount to be     maximum           maximum       registration
to be registered    registered   offering price      aggregate          fee
                                    per share      offering price
________________________________________________________________________________
Common stock          500,000        $44.85 (1)     $22,000,000       $1,816.43
________________________________________________________________________________

(1)  Estimated solely for the purpose of calculating the registration fee
pursuant to Rule 457(h).  The fee is calculated on the basis of the average of
the high and low prices for the Registrant's Common Stock reported on the
Nasdaq National Market System on July 24, 2003.


Page 2

EXPLANATORY NOTE



	This Registration Statement is being filed to register an additional
500,000 shares of Common Stock (the "Common Stock"), of Westamerica
Bancorporation (the "Registrant") as a result of an increase in the number of
shares of Common Stock issuable under the Westamerica Bancorporation Tax
Deferred Savings/Retirement Plan (ESOP) (the "Plan").  The earlier
Registration Statement on Form S-8 filed by the Registrant with the Commission
on July 13, 1988 (File No. 33-23043), as amended by Post-Effective Amendment
No. 1 on August 25, 1988 and Post-Effective Amendment No. 2 on June 29, 1990,
is hereby incorporated by reference.  This incorporation by reference is made
pursuant to General Instruction E of Form S-8 regarding the registration of
additional securities of the same class as other securities for which there
has been filed a Registration Statement on Form S-8 relating to the same
employee benefit plan.






































Page 3

                                PART II
              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Exhibits.

	The following documents filed by the Registrant with the Securities and
Exchange Commission (the "Commission") pursuant to the Securities Act of 1933,
as amended (the "Securities Act"), are incorporated by reference into this
Registration Statement:  (i) the Registrant's Annual Report on Form 10-K filed
with the Commission for the fiscal year ended December 31, 2002 (File No. 001-
09383), (ii) the Registrant's Quarterly Report on Form 10-Q filed with the
Commission for the quarterly period ended March 31, 2003 (File No. 001-09383),
and (iii) the description of the Registrant's Common Stock contained in the
Registrant's Registration Statement on Form 8-A, as amended, filed with the
Commission on November 19, 1999 (File No. 001-09383).
	All documents subsequently filed by the Registrant with the Commission
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
of 1934, as amended, after the date of this Registration Statement, but prior
to the filing of a post-effective amendment to this Registration Statement
which indicates that all securities offered by this Registration Statement have
been sold or which deregisters all such securities then remaining unsold, shall
be deemed to be incorporated by reference into this Registration Statement.
Each document incorporated by reference into this Registration Statement shall
be deemed to be a part of this Registration Statement from the date of filing
of such document with the Commission until the information contained therein is
superseded or updated by any subsequently filed document which is incorporated
by reference into this Registration Statement or by any document which
constitutes part of the prospectus relating to the Plan meeting the
requirements of Section 10(a) of the Securities Act.


Item 6.   Indemnification of Directors and Officers.

Section 317 of the California Corporations Code authorizes a court to
award, or a corporation's board of directors to grant, indemnity to directors,
officers, employees and other agents of the corporation ("Agents") in terms
sufficiently broad to permit such indemnification under certain circumstances
for liabilities (including reimbursement for expenses incurred) arising under
the Securities Act.

Article VII of the Registrant's Restated Articles of Incorporation, as
amended (Exhibit 4.1 hereto) authorizes the Registrant to indemnify its
Agents, through bylaw provisions, agreements, votes of shareholders or
disinterested directors or otherwise, in excess of the indemnification
otherwise permitted by Section 317 of the California Corporations Code,
subject to the applicable limits set forth in Section 204 of the California
Corporations Code with respect to actions for breach of duty to the Registrant
and its shareholders.  Article VII also authorizes the Registrant to provide
insurance for Agents provided that, in cases where the Registrant owns all or
a portion of the shares of the company issuing the insurance policy, such
company and/or the policy must meet certain conditions set forth in Section
317.  Article V of the Registrant's Bylaws provides for mandatory
indemnification of each director of the Registrant except as prohibited by
law.

	The Registrant maintains a directors and officers liability insurance
policy that indemnifies the Registrant's directors and officers against
certain losses in connection with claims made against them for certain
wrongful acts.  In addition, the Registrant has entered into separate
indemnification agreements with its directors and officers that require the
Registrant, among other things, (i) to maintain directors' and officers'
insurance in reasonable amounts in favor of such individuals, and (ii) to
indemnify them against certain liabilities that may arise by reason of their
status or service as Agents of the Registrant to the fullest extent permitted
by California law.

Page 4

Item 8.   Exhibits.

	The following exhibits are filed herewith or incorporated by reference as
part of this Registration Statement:

Exhibit No.			  	  Description
-----------                     -----------

4.1		Restated Articles of Incorporation of the Registrant, as
            amended (incorporated by reference to Exhibit 3(a) to the
            Registrant's Annual Report on Form 10-K for the fiscal year
            ended December 31, 1997, filed with the Securities and
            Exchange Commission on March 30, 1998).

4.2		By-laws of the Registrant, as amended (incorporated by
            reference to Exhibit 3(ii) to the Registrant's Periodic
            Report on Form 10-Q for the fiscal quarter ended March 31,
            2003, filed with the Securities and Exchange Commission on
            May 14, 2003).

5.1		Opinion of Kirkpatrick & Lockhart LLP regarding the legality
            of the shares being registered.

23.1		Consent of KPMG, independent auditors.

23.2		Consent of Kirkpatrick & Lockhart LLP (included in the
            Opinion filed as Exhibit 5.1).

24.1		Power of Attorney (set forth on the signature page of this
            Registration Statement).














Page 5

SIGNATURES

Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of San Rafael, State of California, on this 25th day of
July, 2003.


							WESTAMERICA BANCORPORATION

							By:    /s/ DAVID L. PAYNE
                                                --------------------
							      David L. Payne
							      Chairman, President and Chief
                                                Executive Officer


KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints David L. Payne his or her true and lawful
attorney-in-fact and agent, with full power of substitution and resubstitution,
for him or her and in his or her name, place and stead, in any and all
capacities, to sign any and all amendments to this Registration Statement, and
to file the same, with all exhibits thereto, and other documentation in
connection therewith, with the Securities and Exchange Commission, granting
unto said attorney-in-fact and agent with full power and authority to do and
perform each and every act and thing requisite and necessary to be done in or
about the premises, as fully to all intents and purposes as he or she might or
could do in person, hereby ratifying and confirming all that said attorneys-in-
fact and agents, or their substitute or substitutes may lawfully do or cause to
be done by virtue hereof.

Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
date(s) indicated:

    Signature                        Capacity                      Date
    ---------                        --------                      ----

/s/ DAVID L. PAYNE             Chairman, President and        July 24, 2003
---------------------------    Chief Executive Officer
David L. Payne                 (Principal Executive Officer)

/s/ JENNIFER J. FINGER         Senior Vice President and      July 24, 2003
---------------------------    Chief Financial Officer
Jennifer J. Finger             (Principal Financial Officer)

/s/ DENNIS R. HANSEN           Senior Vice President and      July 24, 2003
---------------------------    Controller (Principal
Dennis R. Hansen               Accounting Officer)

/s/ ETTA ELLEN                 Director                       July 24, 2003
---------------------------
Etta Allen

Page 6

/s/ LOUIS E. BARTOLINI         Director                       July 24, 2003
---------------------------
Louis E. Bartolini

/s/ ARTHUR C. LATNO, JR.       Director                       July 24, 2003
---------------------------
Arthur C. Latno, Jr.

/s/ PATRICK D. LYNCH           Director                       July 24, 2003
---------------------------
Patrick D. Lynch

/s/ CATHERINE COPE MCMILLAN    Director                       July 24, 2003
---------------------------
Catherine Cope McMillan

/s/ RONALD A. NELSON           Director                       July 24, 2003
---------------------------
Ronald A. Nelson

/s/ CARL R. OTTO               Director                       July 24, 2003
---------------------------
Carl R. Otto

/s/ EDWARD B. SYLVESTER        Director                       July 24, 2003
---------------------------
Edward B. Sylvester




























Page 7


EXHIBIT INDEX

Exhibit No.                         Description
-----------                         ------------

   4.1			Restated Articles of Incorporation of
                        the Registrant, as amended (incorporated
                        by reference to Exhibit 3(a) to the
                        Registrant's Annual Report on Form 10-K
                        for the fiscal year ended December 31,
                        1997, filed with the Securities and
                        Exchange Commission on March 30, 1998).


   4.2			By-laws of the Registrant, as amended
                        (incorporated by reference to Exhibit
                        3(ii) to the Registrant's Periodic
                        Report on Form 10-Q for the fiscal
                        quarter ended March 31, 2003, filed
                        with the Securities and Exchange
                        Commission on May 14, 2003).


   5.1			Opinion of Kirkpatrick and Lockhart LLP
                        regarding the legality of the shares
                        being registered.

   23.1			Consent of KPMG LLP, independent auditors.


   23.2			Consent of Kirkpatrick & Lockhart LLP
                        (included in the Opinion filed as Exhibit 5.1).


   24.1			Power of Attorney (set forth on the
                        signature page of this Registration Statement)

















Page 8

Exhibit 5.1





July 25, 2003

Westamerica Bancorporation
1108 Fifth Avenue
San Rafael, California  94901

Ladies and Gentlemen:

	We are counsel to Westamerica Bancorporation (the "Company") and we have
acted as counsel for the Company in connection with the preparation of the
Registration Statement on Form S-8 (the "Registration Statement") to be filed
by the Company with the Securities and Exchange Commission for the registration
under the Securities Act of 1933, as amended, of 500,000 shares of the
Company's common stock, par value $.01 per share (the "Shares"), which are to
be issued from time to time to certain employees of the Company and its
affiliates in connection with the Westamerica Bancorporation Tax Deferred
Savings/Retirement Plan (ESOP) (the "Plan").

	We have examined the originals, certified copies or copies otherwise
identified to our satisfaction as being true copies of the Plan and such other
documents as we have deemed necessary or appropriate for purposes of this
opinion.

	Based on the foregoing, we are of the opinion that the Shares have been
duly and validly authorized and reserved for issuance, and that the Shares,
when issued under the terms of the Plan, will be legally and validly issued,
fully paid and nonassessable.

	We hereby consent to the filing of this opinion as Exhibit 5.1 to the
Registration Statement.

							Yours truly,

                                          By:  /s/ KIRKPATRICK & LOCKHART LLP
                                               ------------------------------














Page 9

Exhibit 23.1






                         Independent Auditors' Consent


The Board of Directors
Westamerica Bancorporation

We consent to the incorporation by reference in the Registration Statement on
Form S-8 pertaining to the registration of 500,000 shares of Westamerica
Bancorporation common stock under the Westamerica Bancorporation Tax Deferred
Savings/Retirement Plan (ESOP) of our report dated January 21, 2003, with
respect to the balance sheets of Westamerica Bancorporation as of December 31,
2002 and 2001 and the related statements of income and comprehensive income,
shareholders' equity and cash flows for each of the years in the three-year
period ended December 31, 2002 which report appears in the December 31, 2002
annual report on Form 10-K of Westamerica Bancorporation.

By: /s/ KPMG LLP
   --------------



San Francisco, California
July 25, 2003
[{"type": "S-8", "sequence": "1", "filename": "s8jul03.txt", "description": "JULY 25, 2003 WESTAMERICA BANCORPORATION S-8", "secsgml_size_bytes": 16136}]
{"company-data": {"conformed-name": "WESTAMERICA BANCORPORATION", "cik": "0000311094", "assigned-sic": "6021", "irs-number": "942156203", "state-of-incorporation": "CA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-107329", "film-number": "03802732"}, "business-address": {"street1": "1108 FIFTH AVE", "city": "SAN RAFAEL", "state": "CA", "zip": "94901", "phone": "(707) 863-8000"}, "mail-address": {"street1": "4550 MANGELS BLVD", "street2": "A-2Y", "city": "FAIRFIELD", "state": "CA", "zip": "94585-1200"}, "former-company": {"former-conformed-name": "INDEPENDENT BANKSHARES CORP", "date-changed": "19830801"}}
Page 1

Registration No. 333-_______

                           SECURITIES AND EXCHANGE COMMISSION
                                WASHINGTON, D.C. 20549
                                     __________

                                      FORM S-8

                               REGISTRATION STATEMENT
                                        UNDER
                              THE SECURITIES ACT OF 1933
                                     __________

                            WESTAMERICA BANCORPORATION
                (Exact name of registrant as specified in its charter)

          California					    94-2156203
(State or other jurisdiction of                  (I.R.S. Employer
 incorporation or organization)	              entification No.)

            1108 Fifth Avenue
         San Rafael, California	                    94901
 (Address of Principal Executive Offices)             (Zip Code)

                            WESTAMERICA BANCORPORATION
                    TAX DEFERRED SAVINGS/RETIREMENT PLAN (ESOP)
                             (Full title of the plan)

                                   David L. Payne
                    Chairman, President and Chief Executive Officer
                              Westamerica Bancorporation
                                    1108 Fifth Avenue
                              San Rafael, California  94901
                        (Name and address of agent for service)

                                    (415) 257-8000
            (Telephone number, including area code, of agent for service)

                            CALCULATION OF REGISTRATION FEE
________________________________________________________________________________
    Title of                        Proposed          Proposed      Amount of
   Securities      Amount to be     maximum           maximum       registration
to be registered    registered   offering price      aggregate          fee
                                    per share      offering price
________________________________________________________________________________
Common stock          500,000        $44.85 (1)     $22,000,000       $1,816.43
________________________________________________________________________________

(1)  Estimated solely for the purpose of calculating the registration fee
pursuant to Rule 457(h).  The fee is calculated on the basis of the average of
the high and low prices for the Registrant's Common Stock reported on the
Nasdaq National Market System on July 24, 2003.

Page 2

EXPLANATORY NOTE

	This Registration Statement is being filed to register an additional
500,000 shares of Common Stock (the "Common Stock"), of Westamerica
Bancorporation (the "Registrant") as a result of an increase in the number of
shares of Common Stock issuable under the Westamerica Bancorporation Tax
Deferred Savings/Retirement Plan (ESOP) (the "Plan").  The earlier
Registration Statement on Form S-8 filed by the Registrant with the Commission
on July 13, 1988 (File No. 33-23043), as amended by Post-Effective Amendment
No. 1 on August 25, 1988 and Post-Effective Amendment No. 2 on June 29, 1990,
is hereby incorporated by reference.  This incorporation by reference is made
pursuant to General Instruction E of Form S-8 regarding the registration of
additional securities of the same class as other securities for which there
has been filed a Registration Statement on Form S-8 relating to the same
employee benefit plan.

Page 3

                                PART II
              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Exhibits.

	The following documents filed by the Registrant with the Securities and
Exchange Commission (the "Commission") pursuant to the Securities Act of 1933,
as amended (the "Securities Act"), are incorporated by reference into this
Registration Statement:  (i) the Registrant's Annual Report on Form 10-K filed
with the Commission for the fiscal year ended December 31, 2002 (File No. 001-
09383), (ii) the Registrant's Quarterly Report on Form 10-Q filed with the
Commission for the quarterly period ended March 31, 2003 (File No. 001-09383),
and (iii) the description of the Registrant's Common Stock contained in the
Registrant's Registration Statement on Form 8-A, as amended, filed with the
Commission on November 19, 1999 (File No. 001-09383).
	All documents subsequently filed by the Registrant with the Commission
pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act
of 1934, as amended, after the date of this Registration Statement, but prior
to the filing of a post-effective amendment to this Registration Statement
which indicates that all securities offered by this Registration Statement have
been sold or which deregisters all such securities then remaining unsold, shall
be deemed to be incorporated by reference into this Registration Statement.
Each document incorporated by reference into this Registration Statement shall
be deemed to be a part of this Registration Statement from the date of filing
of such document with the Commission until the information contained therein is
superseded or updated by any subsequently filed document which is incorporated
by reference into this Registration Statement or by any document which
constitutes part of the prospectus relating to the Plan meeting the
requirements of Section 10(a) of the Securities Act.

Item 6.   Indemnification of Directors and Officers.

Section 317 of the California Corporations Code authorizes a court to
award, or a corporation's board of directors to grant, indemnity to directors,
officers, employees and other agents of the corporation ("Agents") in terms
sufficiently broad to permit such indemnification under certain circumstances
for liabilities (including reimbursement for expenses incurred) arising under
the Securities Act.

Article VII of the Registrant's Restated Articles of Incorporation, as
amended (Exhibit 4.1 hereto) authorizes the Registrant to indemnify its
Agents, through bylaw provisions, agreements, votes of shareholders or
disinterested directors or otherwise, in excess of the indemnification
otherwise permitted by Section 317 of the California Corporations Code,
subject to the applicable limits set forth in Section 204 of the California
Corporations Code with respect to actions for breach of duty to the Registrant
and its shareholders.  Article VII also authorizes the Registrant to provide
insurance for Agents provided that, in cases where the Registrant owns all or
a portion of the shares of the company issuing the insurance policy, such
company and/or the policy must meet certain conditions set forth in Section
317.  Article V of the Registrant's Bylaws provides for mandatory
indemnification of each director of the Registrant except as prohibited by
law.

	The Registrant maintains a directors and officers liability insurance
policy that indemnifies the Registrant's directors and officers against
certain losses in connection with claims made against them for certain
wrongful acts.  In addition, the Registrant has entered into separate
indemnification agreements with its directors and officers that require the
Registrant, among other things, (i) to maintain directors' and officers'
insurance in reasonable amounts in favor of such individuals, and (ii) to
indemnify them against certain liabilities that may arise by reason of their
status or service as Agents of the Registrant to the fullest extent permitted
by California law.

Page 4

Item 8.   Exhibits.

	The following exhibits are filed herewith or incorporated by reference as
part of this Registration Statement:

Exhibit No.			  	  Description
-----------                     -----------

4.1		Restated Articles of Incorporation of the Registrant, as
            amended (incorporated by reference to Exhibit 3(a) to the
            Registrant's Annual Report on Form 10-K for the fiscal year
            ended December 31, 1997, filed with the Securities and
            Exchange Commission on March 30, 1998).

4.2		By-laws of the Registrant, as amended (incorporated by
            reference to Exhibit 3(ii) to the Registrant's Periodic
            Report on Form 10-Q for the fiscal quarter ended March 31,
            2003, filed with the Securities and Exchange Commission on
            May 14, 2003).

5.1		Opinion of Kirkpatrick & Lockhart LLP regarding the legality
            of the shares being registered.

23.1		Consent of KPMG, independent auditors.

23.2		Consent of Kirkpatrick & Lockhart LLP (included in the
            Opinion filed as Exhibit 5.1).

24.1		Power of Attorney (set forth on the signature page of this
            Registration Statement).

Page 5

SIGNATURES

Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of San Rafael, State of California, on this 25th day of
July, 2003.

							WESTAMERICA BANCORPORATION

							By:    /s/ DAVID L. PAYNE
                                                --------------------
							      David L. Payne
							      Chairman, President and Chief
                                                Executive Officer

KNOW ALL MEN BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints David L. Payne his or her true and lawful
attorney-in-fact and agent, with full power of substitution and resubstitution,
for him or her and in his or her name, place and stead, in any and all
capacities, to sign any and all amendments to this Registration Statement, and
to file the same, with all exhibits thereto, and other documentation in
connection therewith, with the Securities and Exchange Commission, granting
unto said attorney-in-fact and agent with full power and authority to do and
perform each and every act and thing requisite and necessary to be done in or
about the premises, as fully to all intents and purposes as he or she might or
could do in person, hereby ratifying and confirming all that said attorneys-in-
fact and agents, or their substitute or substitutes may lawfully do or cause to
be done by virtue hereof.

Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
date(s) indicated:

    Signature                        Capacity                      Date
    ---------                        --------                      ----

/s/ DAVID L. PAYNE             Chairman, President and        July 24, 2003
---------------------------    Chief Executive Officer
David L. Payne                 (Principal Executive Officer)

/s/ JENNIFER J. FINGER         Senior Vice President and      July 24, 2003
---------------------------    Chief Financial Officer
Jennifer J. Finger             (Principal Financial Officer)

/s/ DENNIS R. HANSEN           Senior Vice President and      July 24, 2003
---------------------------    Controller (Principal
Dennis R. Hansen               Accounting Officer)

/s/ ETTA ELLEN                 Director                       July 24, 2003
---------------------------
Etta Allen

Page 6

/s/ LOUIS E. BARTOLINI         Director                       July 24, 2003
---------------------------
Louis E. Bartolini

/s/ ARTHUR C. LATNO, JR.       Director                       July 24, 2003
---------------------------
Arthur C. Latno, Jr.

/s/ PATRICK D. LYNCH           Director                       July 24, 2003
---------------------------
Patrick D. Lynch

/s/ CATHERINE COPE MCMILLAN    Director                       July 24, 2003
---------------------------
Catherine Cope McMillan

/s/ RONALD A. NELSON           Director                       July 24, 2003
---------------------------
Ronald A. Nelson

/s/ CARL R. OTTO               Director                       July 24, 2003
---------------------------
Carl R. Otto

/s/ EDWARD B. SYLVESTER        Director                       July 24, 2003
---------------------------
Edward B. Sylvester

Page 7

EXHIBIT INDEX

Exhibit No.                         Description
-----------                         ------------

   4.1			Restated Articles of Incorporation of
                        the Registrant, as amended (incorporated
                        by reference to Exhibit 3(a) to the
                        Registrant's Annual Report on Form 10-K
                        for the fiscal year ended December 31,
                        1997, filed with the Securities and
                        Exchange Commission on March 30, 1998).

   4.2			By-laws of the Registrant, as amended
                        (incorporated by reference to Exhibit
                        3(ii) to the Registrant's Periodic
                        Report on Form 10-Q for the fiscal
                        quarter ended March 31, 2003, filed
                        with the Securities and Exchange
                        Commission on May 14, 2003).

   5.1			Opinion of Kirkpatrick and Lockhart LLP
                        regarding the legality of the shares
                        being registered.

   23.1			Consent of KPMG LLP, independent auditors.

   23.2			Consent of Kirkpatrick & Lockhart LLP
                        (included in the Opinion filed as Exhibit 5.1).

   24.1			Power of Attorney (set forth on the
                        signature page of this Registration Statement)

Page 8

Exhibit 5.1

July 25, 2003

Westamerica Bancorporation
1108 Fifth Avenue
San Rafael, California  94901

Ladies and Gentlemen:

	We are counsel to Westamerica Bancorporation (the "Company") and we have
acted as counsel for the Company in connection with the preparation of the
Registration Statement on Form S-8 (the "Registration Statement") to be filed
by the Company with the Securities and Exchange Commission for the registration
under the Securities Act of 1933, as amended, of 500,000 shares of the
Company's common stock, par value $.01 per share (the "Shares"), which are to
be issued from time to time to certain employees of the Company and its
affiliates in connection with the Westamerica Bancorporation Tax Deferred
Savings/Retirement Plan (ESOP) (the "Plan").

	We have examined the originals, certified copies or copies otherwise
identified to our satisfaction as being true copies of the Plan and such other
documents as we have deemed necessary or appropriate for purposes of this
opinion.

	Based on the foregoing, we are of the opinion that the Shares have been
duly and validly authorized and reserved for issuance, and that the Shares,
when issued under the terms of the Plan, will be legally and validly issued,
fully paid and nonassessable.

	We hereby consent to the filing of this opinion as Exhibit 5.1 to the
Registration Statement.

							Yours truly,

                                          By:  /s/ KIRKPATRICK & LOCKHART LLP
                                               ------------------------------

Page 9

Exhibit 23.1

                         Independent Auditors' Consent

The Board of Directors
Westamerica Bancorporation

We consent to the incorporation by reference in the Registration Statement on
Form S-8 pertaining to the registration of 500,000 shares of Westamerica
Bancorporation common stock under the Westamerica Bancorporation Tax Deferred
Savings/Retirement Plan (ESOP) of our report dated January 21, 2003, with
respect to the balance sheets of Westamerica Bancorporation as of December 31,
2002 and 2001 and the related statements of income and comprehensive income,
shareholders' equity and cash flows for each of the years in the three-year
period ended December 31, 2002 which report appears in the December 31, 2002
annual report on Form 10-K of Westamerica Bancorporation.

By: /s/ KPMG LLP
   --------------

San Francisco, California
July 25, 2003