<PAGE>
 
 MEDICAL RESOURCES, INC.

Exhibit 11.  Computation of Shares Used For Earnings Per Share Calculation.
 
                                            Quarter ended March 31,
                                               1997         1996
                                            -----------  -----------
 
Primary earnings per share information:
 
Net income per consolidated statements
 of operations                              $ 3,601,825   $1,297,778
Add:  Interest savings from proceeds
      of conversion of outstanding
      warrants and exercise of stock
      options, net of minority
      interest and income taxes
                                            -----------   ----------
     Net income used to compute primary
     earnings per share                     $ 3,601,825   $1,297,778
                                            ===========  ===========
 
 
 
Weighted average number of
 outstanding shares                          19,001,393    8,250,589
Add:  Incremental shares issuable
      on conversion of outstanding
      warrants and exercise of
      stock options                             930,452       82,110
                                            -----------  -----------
Weighted average number of shares
 used to compute primary earnings
 per share                                   19,931,845    8,332,699
                                            ===========  ===========
 
Primary earnings per share:
---------------------------
Primary net income per share               $        .18  $       .16
                                            ===========   ==========




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<PAGE>
 
MEDICAL RESOURCES, INC.

Exhibit 11.  Computation of Shares Used For Earnings Per Share Calculation.

<TABLE> 
<CAPTION> 
                                                            Quarter ended March 31,
                                                               1997        1996
                                                          ------------  ----------
<S>                                                       <C>           <C> 
Fully diluted earnings per share information:   
                                                
Net income per consolidated statements          
 of operations                                             $ 3,601,825  $1,297,778
Add:  Interest savings from proceeds            
      of conversion of outstanding              
      warrants and exercise of stock            
      options, net of minority                  
      interest and income taxes                                21,851
                                                           -----------  ----------
                                                
Net income used to compute fully                
     diluted earnings per share                            $ 3,623,676  $1,297,778
                                                           ===========  ==========
                                                
                                                
Weighted average number of                      
 outstanding shares                                         19,001,393   8,250,589
Add:  Incremental shares issuable               
      on conversion of outstanding              
      warrants and exercise of                  
      stock options                                            930,452     136,584
      Incremental shares issuable on            
      conversion of convertible                 
      subordinated debentures                                  342,500
      Weighted average number of shares                    -----------  ---------- 
                                                
 used to compute fully diluted                  
 earnings per share                                         20,274,345   8,387,173
                                                           ===========  ==========
                                                
Fully diluted earnings per share:               
---------------------------------               
Fully diluted net income per share                          $      .18 $       .16
                                                             =========  ==========
</TABLE> 



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