EXHIBIT 23



            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
            --------------------------------------------------------


We hereby consent to the incorporation by reference in the Registration
Statement on Form S-8 (No. 33-23043) of Westamerica Bancorporation of our report
dated June 26, 2007 relating to the financial statements and supplemental
schedules of the Westamerica Bancorporation Tax Deferred Savings/Retirement Plan
(ESOP) as of December 31, 2006 and 2005 and for the years ended December 31,
2006, 2005, and 2004 appearing in this Annual Report on Form 11-K.


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



Sacramento, California
June 26, 2007