EXHIBIT 23.1
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We consent to the incorporation by reference in Registration Statement (No. 333-107329) on Form S-8 of Westamerica Bancorporation of our report dated June 25, 2012, appearing in this Annual Report on Form 11-K of the Westamerica Bancorporation Tax Deferred Savings/Retirement Plan (ESOP) for the year ended December 31, 2011.
/s/ Crowe Horwath LLP
Crowe Horwath LLP
Sacramento, California
June 25, 2012