<PAGE>
 
                                                                    Exhibit 11.2

                         NEWBRIDGE NETWORKS CORPORATION

                        COMPUTATION OF EARNINGS PER SHARE

         (Accounting principles generally accepted in the United States)
         (Canadian dollars, amounts in thousands except per share data)



<TABLE> 
<CAPTION> 
                                                            for the fiscal quarter ended            for the fiscal year ended
                                                            ----------------------------            -------------------------
                                                       Jul 28,    Oct 27,    Jan 26,    Apr 30,    Apr 30,    Apr 30,    Apr 30,
                                                         1996       1996       1997       1997       1997       1996       1995
                                                         ----       ----       ----       ----       ----       ----       ----
<S>                                                    <C>        <C>        <C>       <C>         <C>        <C>        <C> 
Earnings per share  (U.S. GAAP - Primary)                                                                        
                                                                                                                 
    Net earnings                                       $60,801    $62,781   $(33,909)   $67,244    $156,917   $202,864   $188,390
                                                        ======     ======     ======     ======     =======    =======    =======
                                                                                                                 
    Weighted average number of                                                                                   
       Common Shares outstanding                                                                                 
       at the end of the period                        169,228    170,232    170,941    171,701     170,510    165,842    162,891
                                                                                                                 
    Net effect of dilutive stock options and                                                                     
       shares to be issued in settlement of                                                                      
       litigation, based on the treasury stock                                                                   
       method                                            5,702      4,515       --        4,853       4,015      5,148      3,755
                                                       -------    -------    -------    -------     -------    -------    -------
                                                                                                                 
    Weighted average number of Common                                                                            
       Shares outstanding at the end of the                                                                      
       period as adjusted                              174,930    174,747    170,941    176,554     174,525    170,990    166,646
                                                       =======    =======    =======    =======     =======    =======    =======
                                                                                                                          
    Earnings per share (U.S. GAAP)                          35(c)      36(c)     (20)(c)     38(c)       90(c)   $1.19      $1.13
                                                            ==         ==         ==         ==          ==       ====       ====


Earnings per share  (U.S. GAAP - Fully Diluted)

    Net earnings                                       $60,801    $62,781   $(33,909)   $67,244    $156,917   $202,864   $188,390
                                                        ======     ======     ======     ======     =======    =======    =======
                                                                                                                
    Weighted average number of                                                                                  
       Common Shares outstanding                                                                                
       at the end of the period                        169,228    170,232    170,941    171,701     170,510    165,842    162,891
                                                                                                                 
    Net effect of dilutive stock options and                                                                     
       shares to be issued in settlement of                                                                      
       litigation, based on the treasury stock                                                                   
       method                                            5,702      4,515       --        4,853       4,015      6,938      3,755
                                                       -------    -------    -------    -------     -------    -------    -------
                                                                                                                 
    Weighted average number of Common                                                                            
       Shares outstanding at the end of the                                                                      
       period as adjusted                              174,930    174,747    170,941    176,554     174,525    172,780    166,646
                                                       =======    =======    =======    =======     =======    =======    =======
                                                                                                              
    Earnings per share (U.S. GAAP)                          35(c)      36(c)     (20)(c)     38(c)       90(c)   $1.17      $1.13
                                                            ==         ==         ==         ==          ==       ====       ====


Earnings per share expressed in U.S. dollars

    Daily average exchange rate of a Canadian
       dollar for U.S. dollars as reported by 
       the Federal Reserve Bank of New York            $0.7309    $0.7322    $0.7406    $0.7284     $0.7344    $0.7345    $0.7248

    Primary earnings (loss) per share, in U.S. 
       dollars                                              25(c)      26(c)     (15)(c)     28(c)       66(c)      87(c)      82(c)

    Fully diluted earnings (loss) per
       share, in U.S. dollars                               25(c)      26(c)     (15)(c)     28(c)       66(c)      86(c)      82(c)
</TABLE> 

                                   Page 183