<ARTICLE>                     5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL  INFORMATION  EXTRACTED FROM MEDIMMUNE,
INC'S QUARTERLY REPORT ON FORM 10-Q FOR THE NINE MONTHS ENDED SEPTEMBER 30, 1999
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FILING.

</LEGEND>
<MULTIPLIER>                                  1,000


                                           
<PERIOD-TYPE>                                  9-MOS
<FISCAL-YEAR-END>                              DEC-31-1999
 <PERIOD-END>                                  SEP-30-1999
<CASH>                                            9,366
<SECURITIES>                                    149,944
<RECEIVABLES>                                    23,711
<ALLOWANCES>                                          0
<INVENTORY>                                      28,673
<CURRENT-ASSETS>                                225,509
<PP&E>                                           81,575
<DEPRECIATION>                                        0
<TOTAL-ASSETS>                                  416,408
<CURRENT-LIABILITIES>                            39,526
<BONDS>                                          17,489
<PREFERRED-MANDATORY>                                 0
<PREFERRED>                                           0
<COMMON>                                            633
<OTHER-SE>                                      356,711
<TOTAL-LIABILITY-AND-EQUITY>                    416,408
<SALES>                                         167,397
<TOTAL-REVENUES>                                187,871
<CGS>                                            46,649
<TOTAL-COSTS>                                   156,041
<OTHER-EXPENSES>                                      0
<LOSS-PROVISION>                                      0
<INTEREST-EXPENSE>                                2,332
<INCOME-PRETAX>                                  36,548
<INCOME-TAX>                                     12,935
<INCOME-CONTINUING>                              23,613
<DISCONTINUED>                                        0
<EXTRAORDINARY>                                       0
<CHANGES>                                             0
<NET-INCOME>                                     23,613
<EPS-BASIC>                                      0.41
<EPS-DILUTED>                                      0.37