<PAGE>
 
                                                                    EXHIBIT 11.1
                              SEGUE SOFTWARE, INC.
                STATEMENT RE: COMPUTATION OF PER SHARE EARNINGS
                    (IN THOUSANDS, EXCEPT PER SHARE AMOUNTS)
<TABLE>
<CAPTION>
                                                    Primary               Fully diluted  
                                                    income (loss)         income (loss)  
                                                    per common share      per common share 
                                                    ------------------    ----------------- 
For the three months ended March 31, 1997:
<S>                                              <C>                    <C>  
   Net income                                           $  698                   $  698  
                                                        ======                   ======
   Weighted average common shares outstanding                                          
         during the period                               7,218                    7,218
   Dilutive effect of stock options                        866                      865
   Weighted average common and common                                                  
         equivalent shares outstanding                   8,084                    8,083
                                                        ======                   ======
   Net income per common and common                                                    
         equivalent shares                              $  .09                   $  .09
                                                        ======                   ======
                                                                                       
For the three months ended March 31, 1996:                                             
                                                                                       
   Net income                                           $    2                   $    2
                                                        ======                   ======
   Weighted average common shares outstanding                                          
         during the period                               5,001                    5,146
   Weighted average cheap stock outstanding                                            
         during the period /(1)/                           122                      122
                                                        ------                   ------
   Weighted average common and common                                                  
         equivalent shares outstanding                   5,123                    5,268
                                                        ======                   ======
   Net income (loss) per common and common                                             
         equivalent shares                              $                        $     
                                                            -                        - 
                                                        ======                   ====== 
</TABLE>

/ (1)/ In accordance with the Securities and Exchange Commission Staff
Accounting Bulletin No. 83, issuances of Common Stock and Common Stock
equivalents within one year prior to the initial filing date of the registration
statement, at share prices less than the assumed initial public offering price,
are considered to have been made in anticipation of the public offering which
was completed April 2, 1996.  Accordingly, these equity issuances are treated as
if issued and outstanding, using the treasury stock method, for the three months
ended March 31, 1996.