<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM MEDIMMUNE,
INC'S YEARLY REPORT ON FORM 10-K FOR THE TWELVE MONTHS ENDED DECEMBER 31, 1999
AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FILING
</LEGEND>
<MULTIPLIER> 1,000

                             
<PERIOD-TYPE>                   12-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               DEC-31-1999
<CASH>                                          36,570
<SECURITIES>                                   233,824
<RECEIVABLES>                                   86,894
<ALLOWANCES>                                         0
<INVENTORY>                                     31,777
<CURRENT-ASSETS>                               401,838
<PP&E>                                          87,452
<DEPRECIATION>                                       0
<TOTAL-ASSETS>                                 648,424
<CURRENT-LIABILITIES>                           98,952
<BONDS>                                         10,366
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                           679
<OTHER-SE>                                     536,400
<TOTAL-LIABILITY-AND-EQUITY>                   648,424
<SALES>                                        356,815
<TOTAL-REVENUES>                               383,375
<CGS>                                           90,193
<TOTAL-COSTS>                                  306,556
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               3,176
<INCOME-PRETAX>                                 86,276
<INCOME-TAX>                                   (7,095)
<INCOME-CONTINUING>                             93,371
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                    93,371
<EPS-BASIC>                                       1.47
<EPS-DILUTED>                                     1.33