Westamerica Bancorporation (WABC) 8-K Westamerica Bancorporation Reports First Quarter 2010 Earnings

Exhibit 99.1

FOR IMMEDIATE RELEASE
April 13, 2010

WESTAMERICA BANCORPORATION REPORTS
FIRST QUARTER 2010 EARNINGS

San Rafael, CA: Westamerica Bancorporation (NASDAQ: WABC), parent company of Westamerica Bank, today reported net income applicable to common shareholders for the first quarter of 2010 of $24 million and diluted earnings per common share (“EPS”) of $0.80. First quarter 2010 net income represents an annualized 19 percent return on shareholders’ equity.

“Westamerica remains highly profitable. Our net interest margin rose to 5.60 percent, supported by a low 0.35 percent cost of funding our loan and investment portfolios. Operating expenses remained well contained, declining $800 thousand from the prior quarter,” said Chairman, President and CEO David Payne. “Credit quality remained stable compared to the fourth quarter 2009. Westamerica’s regulatory capital ratios are at historically high levels, providing a safe haven for our depositors,” added Payne.

First quarter 2009 EPS was $1.80 including a gain from Westamerica Bank’s acquisition of assets and assumption of liabilities of the former County Bank from the Federal Deposit Insurance Corporation (“FDIC”). First quarter 2009 results also included a refund of federal income taxes related to 2004. The acquisition gain and tax refund combined to increase EPS by $1.00.

Net interest income on a fully taxable equivalent basis was $57.0 million for the first quarter of 2010, compared to $58.9 million for the fourth quarter of 2009 and to $59.4 million for the first quarter of 2009. The decline in net interest income is due to lower levels of interest-earning assets. Weak economic conditions and deleveraging by businesses and individuals have impacted loan volumes. The first quarter 2010 net interest margin on a fully taxable equivalent basis was 5.60 percent, compared to 5.50 percent and 5.35 percent for the fourth and first quarters of 2009, respectively.

The provision for loan losses was $2.8 million for the first quarter of 2010, compared to $3.3 million for the fourth quarter of 2009, and $1.8 million for the first quarter of 2009. First quarter

3

2010 net loan losses totaled $3.5 million, or 0.66 percent (annualized) of average loans not covered by FDIC indemnification agreements. Comparable net loan loss rates were 0.88 percent and 0.42 percent, respectively, for the fourth and first quarters of 2009.

Noninterest income for the first quarter of 2010 totaled $15.5 million, compared to $15.7 million in the prior quarter. Noninterest income of $64 million in the first quarter 2009 includes a $49 million acquisition gain.

Noninterest expense for the first quarter of 2010 totaled $32.0 million, compared to $32.8 million in the prior quarter. Personnel costs rose in the first quarter 2010 compared to the prior quarter due to merit increases, higher payroll taxes and other employee benefit costs. Offsetting the rise in personnel costs were lower occupancy and equipment expenses, professional fees, and other expenses. Noninterest expense for the first quarter 2009 of $34.1 million includes higher pre-integration expense levels related to the County Bank acquisition. The efficiency ratio (operating expenses divided by net revenues on a fully taxable equivalent basis) was 44 percent in both the first quarter 2010 and fourth quarter 2009.

At March 31, 2010, Westamerica Bancorporation’s tangible common equity-to-asset ratio was 7.9 percent, Westamerica Bancorporation’s total regulatory capital ratio was 15.2 percent, and Westamerica Bank’s total regulatory capital ratio was 15.1 percent.

At March 31, 2010, the Company’s assets totaled $4.7 billion and loans outstanding totaled $3.0 billion.

Westamerica Bancorporation, through its wholly owned subsidiary Westamerica Bank, operates commercial banking and trust offices throughout Northern and Central California.

Westamerica Bancorporation Web Address: www.westamerica.com

For additional information contact:

Westamerica Bancorporation
Robert A. Thorson — SVP & Chief Financial Officer
707-863-6840

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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 report filed on Form 10-K with the Securities and Exchange Commission, for the year ended December 31, 2009, 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.

#######

5

WESTAMERICA BANCORPORATION
FINANCIAL HIGHLIGHTS
March 31, 2010 Public Information April 13, 2010

1. Net Income Summary.

	(dollars in thousands except per-share amounts)
							Q1’10 /						Q1’10 /									3/31’10YTD /
	Q1’10			Q1’09			Q1’09			Q4’09			Q4’09			3/31’10YTD			3/31’09YTD			3/31’09YTD
1 Net Interest Income (Fully Taxable Equivalent)	$	57,029		$	59,359			-3.9	%	$	58,949			-3.3	%	$	57,029		$	59,359			-3.9	%
2 Provision for Loan Losses		2,800			1,800			55.6	%		3,300			-15.1	%		2,800			1,800			55.6	%
3 Noninterest Income:
4 Gain on Acquisition		0			48,844			n/m			0			n/m			0			48,844			n/m
5 Other		15,470			15,124			2.3	%		15,696			-1.4	%		15,470			15,124			2.3	%
6 Total Noninterest Income		15,470			63,968			n/m			15,696			-1.4	%		15,470			63,968			n/m
7 Noninterest Expense		32,031			34,123			-6.1	%		32,836			-2.5	%		32,031			34,123			-6.1	%
8 Income Before Taxes (FTE)		37,668			87,404			n/m			38,509			-2.2	%		37,668			87,404			n/m
9 Income Tax Provision (FTE)		14,092			34,579			n/m			14,348			-1.8	%		14,092			34,579			n/m
10 Net Income		23,576			52,825			n/m			24,161			-2.4	%		23,576			52,825			n/m
11 Preferred Stock Dividends and Discount Accretion		0			578			n/m			812			n/m			0			578			n/m
12 Net Income Applicable to Common Equity	$	23,576		$	52,247			n/m		$	23,349			1.0	%	$	23,576		$	52,247			n/m
13 Average Common Shares Outstanding		29,228			28,876			1.2	%		29,205			0.1	%		29,228			28,876			1.2	%
14 Diluted Average Common Shares Outstanding		29,596			29,105			1.7	%		29,471			0.4	%		29,596			29,105			1.7	%
15 Operating Ratios:
16 Basic Earnings Per Common Share	$	0.81		$	1.81			n/m		$	0.80			1.3	%	$	0.81		$	1.81			n/m
17 Diluted Earnings Per Common Share		0.80			1.80			n/m			0.79			1.0	%		0.80			1.80			n/m
18 Return On Assets (annualized)		1.99	%		4.24	%					1.85	%					1.99	%		4.24	%
19 Return On Common Equity (annualized)		18.8	%		48.0	%					18.8	%					18.8	%		48.0	%
20 Net Interest Margin (FTE) (annualized)		5.60	%		5.35	%					5.50	%					5.60	%		5.35	%
21 Efficiency Ratio (FTE)		44.2	%		27.7	%					44.0	%					44.2	%		27.7	%
22 Dividends Paid Per Common Share	$	0.36		$	0.36			0.0	%	$	0.35			2.9	%	$	0.36		$	0.36			0.0	%
23 Common Dividend Payout Ratio		45	%		20	%					44	%					45	%		20	%

2. Net Interest Income.

	(dollars in thousands)
							Q1’10 /						Q1’10 /									3/31’10YTD /
	Q1’10			Q1’09			Q1’09			Q4’09			Q4’09			3/31’10YTD			3/31’09YTD			3/31’09YTD
1 Interest and Fee Income (FTE)	$	60,563		$	64,192			-5.7	%	$	63,250			-4.2	%	$	60,563		$	64,192			-5.7	%
2 Interest Expense		3,534			4,833			-26.9	%		4,301			-17.8	%		3,534			4,833			-26.9	%
3 Net Interest Income (FTE)	$	57,029		$	59,359			-3.9	%	$	58,949			-3.3	%	$	57,029		$	59,359			-3.9	%
4 Average Earning Assets	$	4,111,345		$	4,475,371			-8.1	%	$	4,268,101			-3.7	%	$	4,111,345		$	4,475,371			-8.1	%
5 Average Interest-Bearing Liabilities		2,846,144			3,155,685			-9.8	%		2,985,494			-4.7	%		2,846,144			3,155,685			-9.8	%
6 Yield on Earning Assets (FTE) (annualized)		5.95	%		5.79	%					5.90	%					5.95	%		5.79	%
7 Cost of Funds (annualized)		0.35	%		0.44	%					0.40	%					0.35	%		0.44	%
8 Net Interest Margin (FTE) (annualized)		5.60	%		5.35	%					5.50	%					5.60	%		5.35	%
9 Interest Expense/Interest-Bearing Liabilities (annualized)		0.50	%		0.62	%					0.57	%					0.50	%		0.62	%
10 Net Interest Spread (FTE) (annualized)		5.45	%		5.17	%					5.33	%					5.45	%		5.17	%

3. Loans & Other Earning Assets.

	(average volume, dollars in thousands)
							Q1’10 /						Q1’10 /									3/31’10YTD /
	Q1’10			Q1’09			Q1’09			Q4’09			Q4’09			3/31’10YTD			3/31’09YTD			3/31’09YTD
1 Total Assets	$	4,812,924		$	4,998,964			-3.7	%	$	5,007,341			-3.9	%	$	4,812,924		$	4,998,964			-3.7	%
2 Total Earning Assets		4,111,345			4,475,371			-8.1	%		4,268,101			-3.7	%		4,111,345			4,475,371			-8.1	%
3 Total Loans		2,996,628			3,135,944			-4.4	%		3,124,583			-4.1	%		2,996,628			3,135,944			-4.4	%
4 Commercial Loans		796,249			885,232			-10.1	%		848,704			-6.2	%		796,249			885,232			-10.1	%
5 Commercial Real Estate Loans		1,238,344			1,191,260			4.0	%		1,265,086			-2.1	%		1,238,344			1,191,260			4.0	%
6 Consumer Loans		962,035			1,059,452			-9.2	%		1,010,793			-4.8	%		962,035			1,059,452			-9.2	%
7 Total Investment Securities		1,114,717			1,339,427			-16.8	%		1,143,518			-2.5	%		1,114,717			1,339,427			-16.8	%
8 Available For Sale (Market Value)		403,950			400,092			1.0	%		392,229			3.0	%		403,950			400,092			1.0	%
9 Held To Maturity		710,767			939,335			-24.3	%		751,289			-5.4	%		710,767			939,335			-24.3	%
10 HTM Unrealized Gain at Period-End		11,183			1,768			n/m			9,335			n/m			11,183			1,768			n/m
11 Loans / Deposits		75.8	%		81.2	%					76.7	%					75.8	%		81.2	%

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WESTAMERICA BANCORPORATION
FINANCIAL HIGHLIGHTS
March 31, 2010 Public Information April 13, 2010

4. Deposits & Other Interest-Bearing Liabilities.

	(average volume, dollars in thousands)
							Q1’10 /						Q1’10 /									3/31’10YTD /
	Q1’10			Q1’09			Q1’09			Q4’09			Q4’09			3/31’10YTD			3/31’09YTD			3/31’09YTD
1 Total Deposits	$	3,955,299		$	3,862,435			2.4	%	$	4,074,105			-2.9	%	$	3,955,299		$	3,862,435			2.4	%
2 Noninterest Demand		1,379,797			1,286,013			7.3	%		1,425,867			-3.2	%		1,379,797			1,286,013			7.3	%
3 Interest-Bearing Transaction		663,519			667,425			-0.6	%		669,519			-0.9	%		663,519			667,425			-0.6	%
4 Savings		965,490			877,729			10.0	%		979,973			-1.5	%		965,490			877,729			10.0	%
5 Time greater than $100K		555,942			664,474			-16.3	%		564,539			-1.5	%		555,942			664,474			-16.3	%
6 Time less than $100K		390,551			366,794			6.5	%		434,207			-10.1	%		390,551			366,794			6.5	%
7 Total Short-Term Borrowings		244,158			552,645			-55.8	%		310,739			-21.4	%		244,158			552,645			-55.8	%
8 Fed Funds Purchased		0			314,856			n/m			0			n/m			0			314,856			n/m
9 Other Short-Term Funds		244,158			237,789			2.7	%		310,739			-21.4	%		244,158			237,789			2.7	%
10 Long-Term Debt		26,484			26,618			-0.5	%		26,517			-0.1	%		26,484			26,618			-0.5	%
11 Shareholders’ Equity		507,406			485,054			4.6	%		514,497			-1.4	%		507,406			485,054			4.6	%
12 Demand Deposits / Total Deposits		34.9	%		33.3	%					35.0	%					34.9	%		33.3	%
13 Transaction & Savings Deposits / Total Deposits		76.1	%		73.3	%					75.5	%					76.1	%		73.3	%

5. Interest Yields Earned & Rates Paid.

	(dollars in thousands)
	Q1’10							Q4’09			Q1’09
	Average		Income/		Yield */			Yield*/			Average		Income/		Yield*/
	Volume		Expense		Rate			Rate			Volume		Expense		Rate
1 Interest & Fees Income Earned
2 Total Earning Assets (FTE)	$	4,111,345	$	60,563		5.95	%		5.90	%	$	4,475,371	$	64,192		5.79	%
3 Total Loans (FTE)		2,996,628		45,624		6.17	%		6.06	%		3,135,944		46,187		5.97	%
4 Commercial Loans (FTE)		796,249		12,205		6.22	%		5.84	%		885,232		12,785		5.86	%
5 Commercial Real Estate Loans		1,238,344		20,294		6.65	%		6.62	%		1,191,260		19,072		6.49	%
6 Consumer Loans		962,035		13,125		5.53	%		5.53	%		1,059,452		14,330		5.49	%
7 Total Investment Securities (FTE)		1,114,717		14,939		5.36	%		5.44	%		1,339,427		18,005		5.38	%
8 Interest Expense Paid
9 Total Earning Assets		4,111,345		3,534		0.35	%		0.40	%		4,475,371		4,833		0.44	%
10 Total Interest-Bearing Liabilities		2,846,144		3,534		0.50	%		0.57	%		3,155,685		4,833		0.62	%
11 Total Interest-Bearing Deposits		2,575,502		2,488		0.39	%		0.45	%		2,576,422		3,784		0.60	%
12 Interest-Bearing Transaction		663,519		217		0.13	%		0.14	%		667,425		205		0.12	%
13 Savings		965,490		739		0.31	%		0.33	%		877,729		900		0.42	%
14 Time less than $100K		390,551		617		0.64	%		0.77	%		366,794		1,452		1.61	%
15 Time greater than $100K		555,942		915		0.67	%		0.80	%		664,474		1,227		0.75	%
16 Total Short-Term Borrowings		244,158		621		1.03	%		1.09	%		552,645		626		0.46	%
17 Fed Funds Purchased		0		0		0.00	%		0.00	%		314,856		151		0.19	%
18 Other Short-Term Funds		244,158		621		1.03	%		1.09	%		237,789		475		0.81	%
19 Long-Term Debt		26,484		425		6.42	%		6.36	%		26,618		423		6.35	%
20 Net Interest Income and Margin (FTE)			$	57,029		5.60	%		5.50	%			$	59,359		5.35	%

* Annualized

6. Noninterest Income.

	(dollars in thousands except per share amounts)
							Q1’10 /						Q1’10 /									3/31’10YTD /
	Q1’10			Q1’09			Q1’09			Q4’09			Q4’09			3/31’10YTD			3/31’09YTD			3/31’09YTD
1 Service Charges on Deposit Accounts	$	8,742		$	8,422			3.8	%	$	9,376			-6.8	%	$	8,742		$	8,422			3.8	%
2 Merchant Credit Card Income		2,221			2,432			-8.7	%		2,250			-1.3	%		2,221			2,432			-8.7	%
3 ATM Fees & Interchange		891			813			9.6	%		901			-1.1	%		891			813			9.6	%
4 Debit Card Fees		1,174			856			37.1	%		1,219			-3.8	%		1,174			856			37.1	%
5 Financial Services Commissions		149			154			-3.2	%		163			-8.9	%		149			154			-3.2	%
6 Mortgage Banking Income		20			17			18.4	%		14			45.1	%		20			17			18.4	%
7 Trust Fees		381			364			4.8	%		373			2.2	%		381			364			4.8	%
8 Other Income		1,892			2,066			-8.4	%		1,400			35.1	%		1,892			2,066			-8.4	%
9 Sub-total		15,470			15,124			2.3	%		15,696			-1.4	%		15,470			15,124			2.3	%
10 Gain on Acquisition		0			48,844			n/m			0			n/m			0			48,844			n/m
11 Total Noninterest Income	$	15,470		$	63,968			n/m		$	15,696			-1.4	%	$	15,470		$	63,968			n/m
12 Operating Ratios:
13 Total Revenue (FTE)	$	72,499		$	123,327			n/m		$	74,645			-2.9	%	$	72,499		$	123,327			n/m
14 Noninterest Income / Revenue (FTE)		21.3	%		51.9	%					21.0	%					21.3	%		51.9	%
15 Service Charges / Avg. Deposits (annualized)		0.90	%		0.88	%					0.91	%					0.90	%		0.88	%
16 Total Revenue Per Avg. Common Share (annualized)	$	10.06		$	17.32			n/m		$	10.14			-0.8	%	$	10.06		$	17.32			n/m

Page 2

WESTAMERICA BANCORPORATION
FINANCIAL HIGHLIGHTS
March 31, 2010 Public Information April 13, 2010

7. Noninterest Expense.

	(dollars in thousands)
							Q1’10 /						Q1’10 /									3/31’10YTD /
	Q1’10			Q1’09			Q1’09			Q4’09			Q4’09			3/31’10YTD			3/31’09YTD			3/31’09YTD
1 Salaries & Benefits	$	15,892		$	16,371			-2.9	%	$	15,170			4.8	%	$	15,892		$	16,371			-2.9	%
2 Occupancy		3,777			5,410			-30.2	%		3,917			-3.6	%		3,777			5,410			-30.2	%
3 Equipment		1,051			1,222			-14.0	%		1,240			-15.3	%		1,051			1,222			-14.0	%
4 Outsourced Data Processing		2,240			2,104			6.4	%		2,260			-0.9	%		2,240			2,104			6.4	%
5 Courier		907			898			1.0	%		927			-2.2	%		907			898			1.0	%
6 Postage		475			462			2.7	%		540			-12.1	%		475			462			2.7	%
7 Telephone		389			387			0.7	%		490			-20.5	%		389			387			0.7	%
8 Professional Fees		663			888			-25.4	%		1,003			-33.9	%		663			888			-25.4	%
9 Stationery & Supplies		350			367			-4.5	%		364			-3.8	%		350			367			-4.5	%
10 Loan Expense		418			994			-58.0	%		342			22.0	%		418			994			-58.0	%
11 Operational Losses		220			195			13.0	%		295			-25.2	%		220			195			13.0	%
12 Amortization of Identifiable Intangibles		1,598			1,685			-5.2	%		1,646			-2.9	%		1,598			1,685			-5.2	%
13 FDIC Insurance Assessment		1,320			157			n/m			1,440			-8.3	%		1,320			157			n/m
14 Other Operating		2,731			2,983			-8.5	%		3,202			-14.7	%		2,731			2,983			-8.5	%
15 Total Noninterest Expense	$	32,031		$	34,123			-6.1	%	$	32,836			-2.5	%	$	32,031		$	34,123			-6.1	%
16 Average (Avg.) Full Time Equivalent Staff		1,032			1,144			-9.8	%		1,056			-2.3	%		1,032			1,144			-9.8	%
17 Avg. Assets / Avg. Full Time Equivalent Staff	$	4,664		$	4,370			6.7	%	$	4,742			-1.6	%	$	4,664		$	4,370			6.7	%
18 Operating Ratios:
19 FTE Revenue / Avg. Full Time Equiv. Staff (annualized)	$	285		$	437			-34.8	%	$	280			1.8	%	$	285		$	437			-34.8	%
20 Noninterest Expense / Avg. Earning Assets (annualized)		3.16	%		3.09	%					3.05	%					3.16	%		3.09	%
21 Noninterest Expense / FTE Revenues		44.2	%		27.7	%					44.0	%					44.2	%		27.7	%

8. Provision for Loan Losses.

	(dollars in thousands)
							Q1’10 /						Q1’10 /									3/31’10YTD /
	Q1’10			Q1’09			Q1’09			Q4’09			Q4’09			3/31’10YTD			3/31’09YTD			3/31’09YTD
1 Average Total Loans	$	2,996,628		$	3,135,944			-4.4	%	$	3,124,583			-4.1	%	$	2,996,628		$	3,135,944			-4.4	%
2 Avg. Total Covered Loans (1)	$	831,161		$	761,855			9.1	%	$	889,101			-6.5	%	$	831,161		$	761,855			9.1	%
3 Avg. Total Non-Covered Loans	$	2,165,467		$	2,374,089			-8.8	%	$	2,235,482			-3.1	%	$	2,165,467		$	2,374,089			-8.8	%
4 Non-Covered Loans:
5 Provision for Loan Losses	$	2,800		$	1,800			55.6	%	$	3,300			-15.1	%	$	2,800		$	1,800			55.6	%
6 Gross Loan Losses		4,456			2,928			52.2	%		6,533			-31.8	%		4,456			2,928			52.2	%
7 Net Loan Losses		3,527			2,467			43.0	%		4,940			-28.6	%		3,527			2,467			43.0	%
8 Recoveries / Gross Loan Losses		21	%		16	%					24	%					21	%		16	%
9 Net Loan Losses / Avg. Non-Covered Loans (a)		0.66	%		0.42	%					0.88	%					0.66	%		0.42	%
10 Provision for Loan Losses / Avg. Non-Covered Loans (a)		0.52	%		0.31	%					0.59	%					0.52	%		0.31	%
11 Provision for Loan Losses / Net Loan Losses		79.4	%		73.0	%					66.8	%					79.4	%		73.0	%

(1)	Covered loans represent purchased loans on which losses are shared with the FDIC per a Loss-Sharing Agreement. Covered loans were recorded at estimated fair value at February 6, 2009, the date of purchase.
(a)	annualized

Page 3

	Public Information April 13, 2010
WESTAMERICA BANCORPORATION
FINANCIAL HIGHLIGHTS
March 31, 2010

9. Credit Quality.

	(dollars in thousands)
							3/31/10 /						3/31/10 /
	3/31/10			3/31/09			3/31/09			12/31/09			12/31/09			9/30/09			6/30/09			12/31/08
1 Non-Covered Nonperforming Loans:
2 Nonperforming Nonaccrual Loans	$	20,230		$	10,943			84.9	%	$	19,837			2.0	%	$	31,352		$	29,603		$	8,883
3 Performing Nonaccrual Loans		57			27			n/m			25			n/m			61			26			1,143
4 Total Nonaccrual Loans		20,287			10,970			84.9	%		19,862			2.1	%		31,413			29,629			10,026
5 Accruing Loans 90+ Days Past Due		746			777			-4.0	%		800			-6.8	%		1,212			614			755
6 Total Non-Covered Nonperforming Loans		21,033			11,747			79.1	%		20,662			1.8	%		32,625			30,243			10,781
7 Non-Covered Repossessed Loan Collateral		14,266			4,756			n/m			12,642			12.8	%		4,319			4,715			3,505
8 Total Non-Covered Nonperforming Assets		35,299			16,503			113.9	%		33,304			6.0	%		36,944			34,958			14,286
9 Covered Nonperforming Loans (1):
10 Nonperforming Nonaccrual Loans		52,431			34,437			52.3	%		66,965			-21.7	%		53,255			65,910			0
11 Performing Nonaccrual Loans		25,731			3,632			n/m			18,183			41.5	%		26,277			16,901			0
12 Total Nonaccrual Loans		78,162			38,069			n/m			85,148			-8.2	%		79,532			82,811			0
13 Accruing Loans 90+ Days Past Due		317			9,866			n/m			210			51.0	%		935			8,622			0
14 Total Covered Nonperforming Loans (1)		78,479			47,935			63.7	%		85,358			-8.1	%		80,467			91,433			0
15 Covered Repossessed Loan Collateral (1)		22,305			13,391			66.6	%		23,297			-4.3	%		18,740			13,691			0
16 Total Covered Nonperforming Assets (1)		100,784			61,326			64.3	%		108,655			-7.2	%		99,207			105,124			0
17 Total Nonperforming Assets	$	136,083		$	77,829			74.8	%	$	141,959			-4.1	%	$	136,151		$	140,082		$	14,286
18 Non-Covered Classified Loans	$	58,245		$	41,453			40.5	%	$	57,241			1.8	%	$	66,810		$	53,359		$	34,028
19 Covered Classified Loans (1)		184,565			169,778			8.7	%		181,516			1.7	%		174,583			153,972			0
20 Total Classified Loans	$	242,810		$	211,231			14.9	%	$	238,757			1.7	%	$	241,393		$	207,331		$	34,028
21 Total Non-Covered Loans Outstanding	$	2,146,580		$	2,356,237			-8.9	%	$	2,201,088			-2.5	%	$	2,267,130		$	2,322,005		$	2,382,426
22 Total Covered Loans Outstanding (1)		809,503			1,089,071			-25.7	%		855,301			-5.4	%		932,656			1,031,643			0
23 Total Loans Outstanding	$	2,956,083		$	3,445,308			-14.2	%	$	3,056,389			-3.3	%	$	3,199,786		$	3,353,648		$	2,382,426
24 Total Assets	$	4,745,495		$	5,428,865			-12.6	%	$	4,975,501			-4.6	%	$	4,971,159		$	5,193,595		$	4,032,934
25 Non-Covered Loans:
26 Allowance for Loan Losses	$	40,316		$	43,803			-8.0	%	$	41,043			-1.8	%	$	42,683		$	43,122		$	44,470
27 Allowance/Non-Covered Loans		1.88	%		1.86	%					1.86	%					1.88	%		1.86	%		1.87	%
28 Non-Covered Nonperforming Loans/Non-Covered Loans		0.98	%		0.50	%					0.94	%					1.44	%		1.30	%		0.45	%
29 Non-Covered Nonperforming Assets/Total Assets		0.74	%		0.30	%					0.67	%					0.74	%		0.67	%		0.35	%
30 Allowance/Non-Covered Nonperforming Loans		192	%		373	%					199	%					131	%		143	%		412	%
31 Covered Loans (1):
32 Fair Value Discount on Covered Loans	$	83,325		$	149,290					$	93,251					$	98,738		$	114,276			n/a
33 Discount/Covered Loans, gross		9.33	%		12.06	%					9.83	%					9.57	%		9.97	%		n/a
34 Covered Nonperforming Assets/Total Assets		2.12	%		1.13	%					2.18	%					2.00	%		2.02	%		n/a
35 Fair Value Discount on Repossessed Loan Collateral	$	0		$	11,178					$	0					$	4,389		$	7			n/a
36 Discount/Covered Repossessed Loan Collateral, gross		0.00	%		45.50	%					0.00	%					18.98	%		0.05	%		n/a

(1) Covered loans and repossessed loan collateral represent purchased assets on which losses are shared with the FDIC per a Loss-Sharing Agreement. Covered assets were recorded at estimated fair value at February 6, 2009, the date of purchase.

Page 4

	Public Information April 13, 2010
WESTAMERICA BANCORPORATION
FINANCIAL HIGHLIGHTS
March 31, 2010

10. Capital.

	(dollars in thousands, except per-share amounts)
							3/31/10 /						3/31/10 /
	3/31/10			3/31/09			3/31/09			12/31/09			12/31/09			9/30/09			6/30/09			12/31/08
1 Common Shareholders’ Equity	$	519,131		$	454,118			14.3	%	$	505,448			2.7	%	$	494,383		$	476,620		$	409,852
2 Preferred Shareholder’s Equity		0			82,550			n/m			0			n/m			41,335			82,611			0
3 Total Shareholders’ Equity		519,131			536,668			-3.3	%		505,448			2.7	%		535,718			559,231			409,852
4 Tier I Regulatory Capital		383,568			394,829			-2.9	%		370,011			3.7	%		394,283			421,048			288,859
5 Total Regulatory Capital		419,541			432,822			-3.1	%		406,339			3.2	%		431,913			458,182			324,455
6 Total Assets		4,745,495			5,428,865			-12.6	%		4,975,501			-4.6	%		4,971,159			5,193,595			4,032,934
7 Risk-Adjusted Assets		2,758,122			2,993,229			-7.9	%		2,803,007			-1.6	%		2,866,814			2,890,291			2,758,866
8 Total Shareholders’ Equity / Total Assets		10.94	%		9.89	%					10.16	%					10.78	%		10.77	%		10.16	%
9 Total Shareholders’ Equity / Total Loans		17.56	%		15.58	%					16.54	%					16.74	%		16.68	%		17.20	%
10 Tier I Capital /Total Assets		8.08	%		7.27	%					7.44	%					7.93	%		8.11	%		7.16	%
11 Tier I Capital / Risk-Adjusted Assets		13.91	%		13.19	%					13.20	%					13.75	%		14.57	%		10.47	%
12 Total Capital / Risk-Adjusted Assets		15.21	%		14.46	%					14.50	%					15.07	%		15.85	%		11.76	%
13 Tangible Common Equity Ratio		7.92	%		5.52	%					7.22	%					6.95	%		6.26	%		7.01	%
14 Common Shares Outstanding		29,206			28,874			1.2	%		29,208			0.0	%		29,207			29,214			28,880
15 Common Equity Per Share	$	17.77		$	15.73			13.0	%	$	17.31			2.7	%	$	16.93		$	16.31		$	14.19
16 Market Value Per Common Share	$	57.65		$	45.56			26.5	%	$	55.37			4.1	%	$	52.00		$	49.61		$	51.15
17 Share Repurchase Programs

	(shares in thousands)
					Q1’10 /						Q1’10 /							3/31’10YTD /
	Q1’10		Q1’09		Q1’09			Q4’09			Q4’09			3/31’10YTD		3/31’09YTD		3/31’09YTD
18 Total Shares Repurchased / Canceled		88		16		n/m			11			n/m			88		16		n/m
19 Average Repurchase Price	$	54.75	$	41.58		31.7	%	$	52.16			5.0	%	$	54.75	$	41.58		31.7	%
20 Net Shares Repurchased (Issued)		2		6		n/m			(1	)		n/m			2		6		n/m

Page 5

	Public Information April 13, 2010
WESTAMERICA BANCORPORATION
FINANCIAL HIGHLIGHTS
March 31, 2010

11. Period-End Balance Sheets.

	(unaudited, dollars in thousands)
							3/31/10 /						3/31/10 /
	3/31/10			3/31/09			3/31/09			12/31/09			12/31/09			9/30/09			6/30/09			12/31/08
1 Assets:
2 Cash and Money Market Assets	$	253,571		$	149,566			69.5	%	$	361,577			-29.9	%	$	180,521		$	169,291		$	139,224
3 Investment Securities Available For Sale		414,987			436,343			-4.9	%		384,208			8.0	%		391,644			407,127			288,454
4 Investment Securities Held to Maturity		690,585			918,745			-24.8	%		726,935			-5.0	%		780,846			830,618			949,325
5 Non-Covered Loans		2,146,580			2,356,237			-8.9	%		2,201,088			-2.5	%		2,267,130			2,322,005			2,382,426
6 Allowance For Loan Losses		(40,316	)		(43,803	)		-8.0	%		(41,043	)		-1.8	%		(42,683	)		(43,122	)		(44,470	)
7 Non-Covered Loans, net		2,106,264			2,312,434			-8.9	%		2,160,045			-2.5	%		2,224,447			2,278,883			2,337,956
8 Covered Loans, net (1)		809,503			1,089,071			-25.7	%		855,301			-5.4	%		932,656			1,031,643			0
9 Total Loans		2,915,767			3,401,505			-14.3	%		3,015,346			-3.3	%		3,157,103			3,310,526			2,337,956
10 Non-Covered Other Real Estate Owned		14,266			4,756			n/m			12,642			12.8	%		4,319			4,715			3,505
11 Covered Other Real Estate Owned, net (1)		22,305			13,391			66.6	%		23,297			-4.3	%		18,740			13,691			0
12 Premises and Equipment		37,423			26,729			40.0	%		38,098			-1.8	%		38,982			26,490			27,351
13 Identifiable Intangible Assets		34,070			41,630			-18.2	%		35,667			-4.5	%		38,264			39,934			15,208
14 Goodwill		121,699			121,699			0.0	%		121,699			0.0	%		121,699			121,699			121,699
15 Interest Receivable and Other Assets		240,822			314,501			-23.4	%		256,032			-5.9	%		239,041			269,504			150,212
16 Total Assets	$	4,745,495		$	5,428,865			-12.6	%	$	4,975,501			-4.6	%	$	4,971,159		$	5,193,595		$	4,032,934
17 Liabilities and Shareholders’ Equity:
18 Deposits:
19 Noninterest Bearing	$	1,376,760		$	1,353,696			1.7	%	$	1,428,432			-3.6	%	$	1,377,215		$	1,334,871		$	1,158,632
20 Interest-Bearing Transaction		653,872			730,153			-10.4	%		669,004			-2.3	%		660,001			716,706			525,153
21 Savings		957,126			968,411			-1.2	%		971,384			-1.5	%		962,823			968,408			745,496
22 Time		907,271			1,204,021			-24.6	%		991,388			-8.5	%		1,024,587			1,137,152			665,773
23 Total Deposits		3,895,029			4,256,281			-8.5	%		4,060,208			-4.1	%		4,024,626			4,157,137			3,095,054
24 Short-Term Borrowed Funds		211,756			441,418			-52.0	%		227,178			-6.8	%		222,030			316,466			457,275
25 Federal Home Loan Bank Advances		10,306			86,772			-88.1	%		85,470			-87.9	%		85,904			86,338			0
25 Debt Financing and Notes Payable		26,464			26,598			-0.5	%		26,497			-0.1	%		26,531			26,564			26,631
26 Liability For Interest, Taxes and Other		82,809			81,128			2.1	%		70,700			17.1	%		76,350			47,859			44,122
27 Total Liabilities		4,226,364			4,892,197			-13.6	%		4,470,053			-5.5	%		4,435,441			4,634,364			3,623,082
28 Shareholders’ Equity:
29 Preferred Stock		0			82,550			n/m			0			n/m			41,335			82,611			0
30 Paid-In Capital		371,982			356,326			4.4	%		368,732			0.9	%		368,032			367,840			354,674
31 Accumulated Other Comprehensive Income		4,796			2,274			n/m			3,714			29.1	%		6,053			1,747			1,040
32 Retained Earnings		142,353			95,518			49.0	%		133,002			7.0	%		120,298			107,033			54,138
33 Total Common Equity		519,131			454,118			14.3	%		505,448			2.7	%		494,383			476,620			409,852
34 Total Shareholders’ Equity		519,131			536,668			-3.3	%		505,448			2.7	%		535,718			559,231			409,852
35 Total Liabilities and Shareholders’ Equity	$	4,745,495		$	5,428,865			-12.6	%	$	4,975,501			-4.6	%	$	4,971,159		$	5,193,595		$	4,032,934

(1) Covered loans and other real estate owned represent purchased assets on which losses are shared with the FDIC per a Loss-Sharing Agreement. Covered assets were recorded at estimated fair value at February 6, 2009, the date of purchase.

Page 6

	Public Information April 13, 2010
WESTAMERICA BANCORPORATION
FINANCIAL HIGHLIGHTS
March 31, 2010

12. Income Statements.

	(unaudited, dollars in thousands, except per-share amounts)
					Q1’10 /					Q1’10 /							3/31’10YTD /
	Q1’10		Q1’09		Q1’09			Q4’09		Q4’09			3/31’10YTD		3/31’09YTD		3/31’09YTD
1 Interest and Fee Income:
2 Loans	$	44,702	$	45,095		-0.9	%	$	46,653		-4.2	%	$	44,702	$	45,095		-0.9	%
3 Money Market Assets and Funds Sold		1		1		n/m			0		n/m			1		1		n/m
4 Investment Securities Available For Sale		3,895		3,739		4.2	%		3,996		-2.6	%		3,895		3,739		4.2	%
5 Investment Securities Held to Maturity		7,405		10,350		-28.4	%		7,847		-5.6	%		7,405		10,350		-28.4	%
6 Total Interest Income		56,003		59,185		-5.4	%		58,496		-4.3	%		56,003		59,185		-5.4	%
7 Interest Expense:
8 Transaction Deposits		217		205		5.5	%		238		-9.1	%		217		205		5.5	%
9 Savings Deposits		739		900		-17.9	%		803		-8.0	%		739		900		-17.9	%
10 Time Deposits		1,532		2,679		-42.8	%		1,983		-22.7	%		1,532		2,679		-42.8	%
11 Short-Term Borrowed Funds		621		626		-0.8	%		855		-27.4	%		621		626		-0.8	%
12 Debt Financing and Notes Payable		425		423		0.5	%		422		0.7	%		425		423		0.5	%
13 Total Interest Expense		3,534		4,833		-26.9	%		4,301		-17.8	%		3,534		4,833		-26.9	%
14 Net Interest Income		52,469		54,352		-3.5	%		54,195		-3.2	%		52,469		54,352		-3.5	%
15 Provision for Loan Losses		2,800		1,800		55.6	%		3,300		-15.1	%		2,800		1,800		55.6	%
16 Noninterest Income:
17 Service Charges on Deposit Accounts		8,742		8,422		3.8	%		9,376		-6.8	%		8,742		8,422		3.8	%
18 Merchant Credit Card		2,221		2,432		-8.7	%		2,250		-1.3	%		2,221		2,432		-8.7	%
19 ATM Fees & Interchange		891		813		9.6	%		901		-1.1	%		891		813		9.6	%
20 Debit Card Fees		1,174		856		37.1	%		1,219		-3.8	%		1,174		856		37.1	%
21 Financial Services Commissions		149		154		-3.2	%		163		-8.9	%		149		154		-3.2	%
22 Mortgage Banking		20		17		18.4	%		14		45.1	%		20		17		18.4	%
23 Trust Fees		381		364		4.8	%		373		2.2	%		381		364		4.8	%
24 Gain on Acquisition		0		48,844		n/m			0		n/m			0		48,844		n/m
25 Other		1,892		2,066		-8.4	%		1,400		35.1	%		1,892		2,066		-8.4	%
26 Total Noninterest Income		15,470		63,968		n/m			15,696		-1.4	%		15,470		63,968		n/m
27 Noninterest Expense:
28 Salaries and Related Benefits		15,892		16,371		-2.9	%		15,170		4.8	%		15,892		16,371		-2.9	%
29 Occupancy		3,777		5,410		-30.2	%		3,917		-3.6	%		3,777		5,410		-30.2	%
30 Equipment		1,051		1,222		-14.0	%		1,240		-15.3	%		1,051		1,222		-14.0	%
31 Outsourced Data Processing		2,240		2,104		6.4	%		2,260		-0.9	%		2,240		2,104		6.4	%
32 Amortization of Identifiable Intangibles		1,598		1,685		-5.2	%		1,646		-2.9	%		1,598		1,685		-5.2	%
33 Professional Fees		663		888		-25.4	%		1,003		-33.9	%		663		888		-25.4	%
34 FDIC Insurance Assessment		1,320		157		n/m			1,440		-8.3	%		1,320		157		n/m
35 Other		5,490		6,286		-12.7	%		6,160		-10.9	%		5,490		6,286		-12.7	%
36 Total Noninterest Expense		32,031		34,123		-6.1	%		32,836		-2.5	%		32,031		34,123		-6.1	%
37 Income Before Income Taxes		33,108		82,397		n/m			33,755		-1.9	%		33,108		82,397		n/m
38 Income Tax Provision		9,532		29,572		n/m			9,594		-0.6	%		9,532		29,572		n/m
39 Net Income		23,576		52,825		n/m			24,161		-2.4	%		23,576		52,825		n/m
40 Preferred Stock Dividends and Discount Accretion		0		578		n/m			812		n/m			0		578		n/m
41 Net Income Applicable to Common Equity	$	23,576	$	52,247		n/m		$	23,349		1.0	%	$	23,576	$	52,247		n/m
42 Average Common Shares Outstanding		29,228		28,876		1.2	%		29,205		0.1	%		29,228		28,876		1.2	%
43 Diluted Average Common Shares Outstanding		29,596		29,105		1.7	%		29,471		0.4	%		29,596		29,105		1.7	%
44 Per Common Share Data:
45 Basic Earnings	$	0.81	$	1.81		n/m		$	0.80		1.3	%	$	0.81	$	1.81		n/m
46 Diluted Earnings		0.80		1.80		n/m			0.79		1.0	%		0.80		1.80		n/m
47 Dividends Paid		0.36		0.36		0.0	%		0.35		2.9	%		0.36		0.36		0.0	%

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