<PAGE>
 
                          ARONEX PHARMACEUTICALS, INC.

                                                                    Exhibit 11.1
                                                                    ------------

             Statement Regarding Computation of Per Share Earnings

The following reflects the information used in calculating the number of shares
in the computation of net loss per share for each of the periods set forth in
the Statements of Operations.
<TABLE>
<CAPTION>
 
                                                                                                  AVERAGE                   LOSS
                                                                      DAYS         SHARES          SHARES                    PER
                                                        SHARES     OUTSTANDING     X DAYS       OUTSTANDING      LOSS       SHARE
<S>                                                     <C>        <C>            <C>          <C>               <C>        <C> 
QUARTER ENDED SEPTEMBER 30, 1995:
                                                     5,233,599         3        15,700,797
                                                     5,233,978        18        94,211,604
                                                     5,235,493        51       267,010,143
                                                     9,128,928        20       182,578,560
                                                                      92       559,501,104   /92   6,081,534   (9,817,000)  (1.61)
 
NINE MONTHS ENDED SEPTEMBER 30, 1995:
                                                     5,202,476         2        10,404,952
                                                     5,214,976         2        10,429,952
                                                     5,221,604        82       428,171,528
                                                     5,232,463        57       298,250,391
                                                     5,233,599        38       198,876,762
                                                     5,233,599         3        15,700,797
                                                     5,233,978        18        94,211,604
                                                     5,235,493        51       267,010,143
                                                     9,128,928        20       182,578,560
                                                                     273     1,505,634,689   /273  5,515,145  (13,769,000)  (2.50)
 
QUARTER ENDED SEPTEMBER 30, 1996:
                                                    14,526,802        23       334,116,446
                                                    14,531,016         1        14,531,016
                                                    14,543,516        20       290,870,320
                                                    14,543,736         1        14,543,736
                                                    14,544,318        18       261,797,724
                                                    14,545,238         2        29,090,476
                                                    14,545,321         7       101,817,247
                                                    14,555,018        14       203,770,252
                                                    14,556,217         5        72,781,085
                                                    14,557,089         1        14,557,089
                                                                      92     1,337,875,391   /92  14,542,124   (2,022,000)  (0.14)
</TABLE>
<PAGE>
 
<TABLE> 
<CAPTION> 

                                                                                                                        Exhibit 11.1
                                                                                                                        ------------

                                                                                                                        continued

                                                                                                  AVERAGE                   LOSS
                                                                      DAYS         SHARES          SHARES                    PER
                                                        SHARES     OUTSTANDING     X DAYS       OUTSTANDING      LOSS       SHARE
<S>                                                     <C>        <C>            <C>          <C>               <C>        <C> 

NINE MONTHS ENDED SEPTEMBER 30, 1996:
                                                        10,380,056      1       10,380,056
                                                        10,390,003     10      103,900,030
                                                        10,409,608      4       41,638,432
                                                        10,418,676      2       20,837,352          
                                                        10,478,786      1       10,478,786          
                                                        10,046,458      3       30,139,374          
                                                        10,598,792      1       10,598,792          
                                                        10,678,561      2       21,357,122          
                                                        10,680,653      1       10,680,653          
                                                        10,680,903      3       32,042,709          
                                                        10,710,132      4       42,840,528          
                                                        10,718,504      6       64,311,024          
                                                        10,727,170      4       42,908,680          
                                                        10,728,565      1       10,728,565          
                                                        10,729,263      1       10,729,263          
                                                        10,729,394      7       75,105,758           
                                                        10,731,487     19      203,898,253
                                                        10,742,559      7       75,197,913          
                                                        10,771,115      2       21,542,230          
                                                        10,775,477      2       21,550,954          
                                                        10,776,991      4       43,107,964          
                                                        10,784,842      1       10,784,842          
                                                        10,812,921      1       10,812,921          
                                                        10,832,546      2       21,665,092          
                                                        10,847,725      3       32,543,175          
                                                        10,848,023      5       54,240,115          
                                                        10,849,767      7       75,948,369          
                                                        10,851,626      3       32,554,878          
                                                        10,858,605      1       10,858,605          
                                                        10,862,095      2       21,724,190          
                                                        10,962,004      1       10,962,004          
                                                        10,962,593      4       43,850,372          
                                                        10,965,241      2       21,930,482          
                                                        10,965,939      1       10,965,939          
                                                        10,967,993      6       65,807,958          
                                                        10,927,354      5       54,636,770          
                                                        10,997,354      2       21,994,708          
                                                        10,978,310      7       76,848,170          
                                                        10,983,980      4       43,935,920          
                                                        10,989,215      1       10,989,215          
                                                        13,992,587      1       13,992,587          
                                                        13,996,077      1       13,996,077          
                                                        13,996,949      6       83,981,694          
                                                        14,446,949      1       14,446,949          
                                                        14,453,492      5       72,267,460          
                                                        14,456,109      5       72,280,545          
                                                        14,465,806      1       14,465,806          
                                                        14,472,786      2       28,945,572          
                                                        14,473,658      1       14,473,658          
                                                        14,478,658      3       43,435,974          
                                                        14,481,500      1       14,481,500          
                                                        14,483,680      3       43,451,040          
                                                        14,484,059      1       14,484,059          
                                                        14,485,899      2       28,971,798          
                                                        14,488,079      3       43,464,237          
                                                        14,526,802      3       43,580,406           
                                                        14,526,802     23      334,116,446
                                                        14,531,016      1       14,531,016
                                                        14,543,516     20      290,870,320
                                                        14,543,736      1       14,543,736
                                                        14,544,318     18      261,797,724
                                                        14,545,238      2       29,090,476
                                                        14,545,321      7      101,817,247
                                                        14,555,018     14      203,770,252
                                                        14,556,217      5       72,781,085
                                                        14,557,089      1       14,557,089
                                                                      274    3,435,622,916   /274  12,538,770  (6,422,000)  (0.51) 
</TABLE>