<ARTICLE>                     5
<CIK>                         0001010915
<NAME>                        MICROCIDE PHARMACEUTICALS, INC.
<MULTIPLIER>                  1,000
<CURRENCY>                    U.S. DOLLARS
       
                           
<PERIOD-TYPE>                 3-MOS
<FISCAL-YEAR-END>                              DEC-31-1998
<PERIOD-START>                                 JUL-01-1998
<PERIOD-END>                                   Sep-30-1998
<EXCHANGE-RATE>                                     1
<CASH>                                          1,970
<SECURITIES>                                   28,548
<RECEIVABLES>                                   1,743
<ALLOWANCES>                                        0
<INVENTORY>                                         0
<CURRENT-ASSETS>                               32,905
<PP&E>                                         18,884
<DEPRECIATION>                                  8,957
<TOTAL-ASSETS>                                 43,167
<CURRENT-LIABILITIES>                           2,896
<BONDS>                                             0
<PREFERRED-MANDATORY>                               0
<PREFERRED>                                         0
<COMMON>                                       64,484
<OTHER-SE>                                      1,759
<TOTAL-LIABILITY-AND-EQUITY>                   43,167
<SALES>                                             0
<TOTAL-REVENUES>                                2,843
<CGS>                                               0
<TOTAL-COSTS>                                   5,703
<OTHER-EXPENSES>                                    0
<LOSS-PROVISION>                                    0
<INTEREST-EXPENSE>                                  6
<INCOME-PRETAX>                                (2,404)
<INCOME-TAX>                                        0
<INCOME-CONTINUING>                            (2,404)
<DISCONTINUED>                                      0
<EXTRAORDINARY>                                     0
<CHANGES>                                           0
<NET-INCOME>                                   (2,404)
<EPS-PRIMARY>                                   (0.22)
<EPS-DILUTED>                                   (0.22)