Page 32

Exhibit 32.1



CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


In connection with the Quarterly Report of Westamerica Bancorporation (the
Company) on Form 10-Q for the period ending March 31, 2007 as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), I,
David L. Payne, Chief Executive Officer of the Company, certify, pursuant
to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of section 13(a) or 15(d)
of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material
respects, the financial condition and results of operations of the Company.







/s/  David L. Payne                                          May 4, 2007
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David L. Payne                                               Date
Chairman, President and Chief Executive Officer