<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
                                            ===========   ==========
<PAGE>
 
 MEDICAL RESOURCES, INC.

Exhibit 11.  Computation of Shares Used For Earnings Per Share Calculation.
 
<TABLE> 
<CAPTION> 
                                                                              Quarter ended March 31,
                                                                                1997         1996
                                                                             ----------   ----------
Fully diluted earnings per share information:
<S>                                                                         <C>           <C>
 
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>