<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM CEPHALON,
INC.'S FORM 10Q FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30,1997 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<CIK> 0000873364
<NAME> CEPHALON, INC.
       
                             
<PERIOD-TYPE>                   9-MOS
<FISCAL-YEAR-END>                          DEC-31-1997
<PERIOD-START>                             JAN-01-1997
<PERIOD-END>                               SEP-30-1997
<CASH>                                      15,003,000
<SECURITIES>                               117,631,000
<RECEIVABLES>                                6,681,000
<ALLOWANCES>                                         0
<INVENTORY>                                          0
<CURRENT-ASSETS>                           139,987,000
<PP&E>                                      32,570,000
<DEPRECIATION>                              10,560,000
<TOTAL-ASSETS>                             164,970,000
<CURRENT-LIABILITIES>                       20,051,000
<BONDS>                                     41,626,000
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                       259,000
<OTHER-SE>                                 100,671,000
<TOTAL-LIABILITY-AND-EQUITY>               164,970,000
<SALES>                                              0
<TOTAL-REVENUES>                            14,116,000
<CGS>                                                0
<TOTAL-COSTS>                               63,994,000
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                           2,475,000
<INCOME-PRETAX>                           (46,361,000)
<INCOME-TAX>                                         0
<INCOME-CONTINUING>                                  0
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                              (46,361,000)
<EPS-PRIMARY>                                   (1.84)
<EPS-DILUTED>                                        0