Exhibit 11

Simpson Manufacturing Co., Inc. and Subsidiaries

Computation of Earnings Per Common Share

For the Three Years Ended December 31, 2003, 2002 and 2001

Basic Earnings per Share

	2003		2002		2001
Weighted average number of common shares outstanding	24,562,958		24,465,067		24,211,094
Shares issuable pursuant to stock bonus plan	8,800		5,000		5,400
Number of shares for computation of basic net income per share	24,571,758		24,470,067		24,216,494
Net income for computation of basic net income per share	$	60,562,224	$	51,934,147	$	40,518,126
Basic net income per share	$	2.46	$	2.12	$	1.67

Simpson Manufacturing Co., Inc. and Subsidiaries

Computation of Earnings Per Common Share

For the Three Years Ended December 31, 2003, 2002 and 2001

Diluted Earnings per Share

	2003		2002		2001
Weighted average number of common shares outstanding	24,562,958		24,465,067		24,211,094
Shares issuable pursuant to employee stock option plans, less shares assumed repurchased at the average fair value during the period	417,917		333,064		408,948
Shares issuable pursuant to the independent director stock option plan, less shares assumed repurchased at the average fair value during the period	5,818		4,418		6,258
Shares issuable pursuant to stock bonus plan	8,800		5,000		5,400
Number of shares for computation of diluted net income per share	24,995,493		24,807,549		24,631,700
Net income for computation of diluted net income per share	$	60,562,224	$	51,934,147	$	40,518,126
Diluted net income per share	$	2.42	$	2.09	$	1.64