Westamerica Bank

July 17, 2007

For Immediate Release

San Rafael, CA: Westamerica Bancorporation (NASDAQ: WABC), parent company of Westamerica Bank, today reported quarterly net income for the second quarter of 2007 of $22.4 million, or $0.74 diluted earnings per share, compared to net income of $24.5 million, or $0.77 diluted earnings per share for the second quarter of 2006. For the second quarter of 2007, return on assets (ROA) was 1.92 percent and return on equity (ROE) was 21.9 percent.

Net income for the six months ended June 30, 2007 was $45.9 million or $1.50 diluted earnings per share compared to $50.6 million or $1.58 diluted earnings per share for the first six months of 2006. For the first six months of 2007, ROA and ROE were 1.97 percent and 22.5 percent, respectively.

“The competitive environment remains fierce for both loans and deposits, with continued pressure on net interest margins. While working to stabilize our margin, we are also focused on increasing our non-interest revenues and containing our expenses,” said Chairman, President and CEO David Payne. “Our noninterest income increased 4.5 percent in the second quarter 2007 from the same period in 2006, while our expenses were reduced 6.2 percent from the year ago quarter. Our return on shareholders’ equity at 21.9 percent for the second quarter 2007 remains relatively high for the banking industry,” Payne added.

Net interest income on a taxable equivalent basis was $46.1 million for the second quarter of 2007, compared to $51.5 million reported for the second quarter of 2006. The reduced net interest income is attributable to a lower net interest margin and lower average earning assets. Competition for deposits has caused funding costs to rise at a faster pace than earning asset yields. Loan yields have also been impacted by competition. The second quarter 2007 net interest margin on a taxable equivalent basis was 4.36 percent, compared to 4.41 percent for the prior quarter and 4.58 percent for the second quarter of 2006.

The provision for loan losses was $75 thousand for the second quarter of 2007 unchanged from the prior quarter and down from $150 thousand for the second quarter of 2006. Net charge-offs for the second quarter of 2007 totaled $1.5 million, or 0.24 percent (annualized) of average loans compared to 0.08 (annualized) and 0.04 percent (annualized) of average loans for the prior quarter and second quarter of 2006, respectively. Non-performing loans and repossessed loan collateral at June 30, 2007 totaled $5.8 million, increased from $5.5 million at March 31, 2007.

Noninterest income for the second quarter of 2007 was $14.7 million, compared to $15.3 million for the previous quarter and $14.1 million for the second quarter 2006.

The change in noninterest income from the prior quarter includes:

• Increased deposit service charges ($188 thousand)
• Increased merchant card processing fees ($319 thousand)
• $822 thousand gain from company owned life insurance realized in the first quarter 2007.

The change in noninterest income from the second quarter 2006 includes:

• Increased deposit service charges ($530 thousand)
• Increased merchant card processing fees ($376 thousand)

Noninterest expense for the second quarter of 2007 totaled $24.7 million, unchanged from the prior quarter, but down from $26.3 million for the second quarter of 2006. The decrease in expenses from the second quarter of 2006 was primarily due to lower personnel, equipment, professional, telephone, and intangible amortization costs. The second quarter 2007 efficiency ratio (expenses divided by revenues) was 40.7 percent, compared to 39.7 percent for the prior quarter and 40.2 percent for the second quarter of 2006.

Shareholders' equity at June 30, 2007 was $408 million, reduced from $420 million at March 31, 2007. The Company's total regulatory capital ratio was 10.8 percent at June 30, 2007 compared to 11.0 percent at March 31, 2007; both measurements exceed the "well-capitalized" level of 10 percent under regulatory requirements.

Westamerica Bancorporation, through its wholly owned subsidiary Westamerica Bank, operates 87 branches and two trust offices throughout 21 Northern and Central California counties. At June 30, 2007, the Company's total assets and total loans outstanding were $4.6 billion and $2.5 billion, respectively.



Quarterly Financial Highlights



FORWARD-LOOKING INFORMATION:

The following appears in accordance with the Private Securities Litigation Reform Act of 1995:

This press release may contain forward-looking statements about the Company, including descriptions of plans or objectives of its management for future operations, products or services, and forecasts of its revenues, earnings or other measures of economic performance. Forward-looking statements can be identified by the fact that they do not relate strictly to historical or current facts. They often include the words "believe," "expect," "anticipate," "intend," "plan," "estimate," or words of similar meaning, or future or conditional verbs such as "will," "would," "should," "could," or "may."

Forward-looking statements, by their nature, are subject to risks and uncertainties. A number of factors - many of which are beyond the Company's control - could cause actual conditions, events or results to differ significantly from those described in the forward-looking statements. The Company's most recent annual and quarterly reports filed with the Securities and Exchange Commission, including the Company's Form 10-Q for the quarter ended March 31, 2007, and Form 10-K for the year ended December 31, 2006, describe some of these factors, including certain credit, market, operational, liquidity and interest rate risks associated with the Company's business and operations. Other factors described in these reports include changes in business and economic conditions, competition, fiscal and monetary policies, disintermediation, legislation including the Sarbanes-Oxley Act of 2002 and the Gramm-Leach-Bliley Act of 1999, and mergers and acquisitions.

Forward-looking statements speak only as of the date they are made. The Company does not undertake to update forward-looking statements to reflect circumstances or events that occur after the date forward looking statements are made.

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