<TABLE> <S> <C>

<PAGE>
 
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM JUNE 30,
1997 FIRST FINANCIAL BANCORP 10-Q AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE
TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>                     <C>
<PERIOD-TYPE>                   3-MOS                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1997             DEC-31-1997
<PERIOD-START>                             APR-01-1997             JAN-01-1997
<PERIOD-END>                               JUN-30-1997             JUN-30-1997
<CASH>                                           6,163                   6,163
<INT-BEARING-DEPOSITS>                               0                       0
<FED-FUNDS-SOLD>                                 3,300                   3,300
<TRADING-ASSETS>                                     0                       0
<INVESTMENTS-HELD-FOR-SALE>                     56,429                  56,429
<INVESTMENTS-CARRYING>                           1,788                   1,788
<INVESTMENTS-MARKET>                             1,923                   1,923
<LOANS>                                         58,377                  58,377
<ALLOWANCE>                                      1,493                   1,493
<TOTAL-ASSETS>                                 136,770                 136,770
<DEPOSITS>                                     123,671                 123,671
<SHORT-TERM>                                         0                       0
<LIABILITIES-OTHER>                                717                     717
<LONG-TERM>                                          0                       0
<PREFERRED-MANDATORY>                                0                       0
<PREFERRED>                                          0                       0
<COMMON>                                         7,428                   7,428
<OTHER-SE>                                       4,954                   4,954
<TOTAL-LIABILITIES-AND-EQUITY>                 136,770                 136,770
<INTEREST-LOAN>                                  1,504                   3,328
<INTEREST-INVEST>                                  977                   1,645
<INTEREST-OTHER>                                    67                     202
<INTEREST-TOTAL>                                 2,548                   5,175
<INTEREST-DEPOSIT>                                 960                   1,785
<INTEREST-EXPENSE>                                 960                   1,785
<INTEREST-INCOME-NET>                            1,588                   3,390
<LOAN-LOSSES>                                       20                    (60)
<SECURITIES-GAINS>                                   0                       0
<EXPENSE-OTHER>                                  1,698                   3,346
<INCOME-PRETAX>                                    281                     821
<INCOME-PRE-EXTRAORDINARY>                         281                     821
<EXTRAORDINARY>                                      0                       0
<CHANGES>                                            0                       0
<NET-INCOME>                                       206                     546
<EPS-PRIMARY>                                      .15                     .40
<EPS-DILUTED>                                      .15                     .40
<YIELD-ACTUAL>                                    5.22                    5.97
<LOANS-NON>                                        609                     609
<LOANS-PAST>                                        14                      14
<LOANS-TROUBLED>                                 1,132                   1,132
<LOANS-PROBLEM>                                      0                       0
<ALLOWANCE-OPEN>                                 1,464                   1,207
<CHARGE-OFFS>                                        4                       8
<RECOVERIES>                                        13                     354
<ALLOWANCE-CLOSE>                                1,493                   1,493
<ALLOWANCE-DOMESTIC>                             1,493                   1,493
<ALLOWANCE-FOREIGN>                                  0                       0
<ALLOWANCE-UNALLOCATED>                            751                     751
        

</TABLE>