SIMPSON MANUFACTURING CO., INC. AND SUBSIDIARIES
                   Computation of Earnings Per Common Share
          For the Three Years Ended December 31, 1998, 1997 and 1996

                                  Exhibit 11

                           Basic Earnings per Share


                                            1998            1997            1996
                                        ------------    ------------    ------------
                                                               
Weighted average number of 
  common shares outstanding               11,556,629      11,471,217      11,422,995

Shares issuable pursuant to 
  stock bonus plan                             3,825           3,375           1,950
                                        ------------    ------------    ------------
Number of shares for computation 
  of basic net income per share           11,560,454      11,474,592      11,424,945
                                        ============    ============    ============

Net income for computation of 
 basic net income per share             $ 31,141,523    $ 25,985,779    $ 19,720,638
                                        ============    ============    ============

Basic net income per share              $       2.69    $       2.26    $       1.73
                                        ============    ============    ============







               SIMPSON MANUFACTURING CO., INC. AND SUBSIDIARIES
                   Computation of Earnings Per Common Share
          For the Three Years Ended December 31, 1998, 1997 and 1996

                            Exhibit 11 (continued)

                          Diluted Earnings per Share

                                            1998            1997            1996
                                        ------------    ------------    ------------
                                                               
Weighted average number of 
  common shares outstanding               11,556,629      11,471,217      11,422,995

Shares issuable pursuant to 
  employee stock option plans, 
  less shares assumed repurchased 
  at the average fair value 
  during the period                          483,361         486,337         326,604

Shares issuable pursuant to the 
  independent director stock 
  option plan, less shares assumed 
  repurchased at the average fair 
  value during the period                      4,382           5,021           3,635

Shares issuable pursuant to 
  stock bonus plan                             3,825           3,375           1,950
                                        ------------    ------------    ------------
Number of shares for computation 
  of diluted net income per share         12,048,197      11,965,950      11,755,184
                                        ============    ============    ============
Net income for computation of 
  diluted net income per share          $ 31,141,523    $ 25,985,779    $ 19,720,638
                                        ============    ============    ============
Diluted net income per share            $       2.58    $       2.17    $       1.68
                                        ============    ============    ============