<TABLE> <S> <C>

<PAGE>
<ARTICLE> 9
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
QUARTERLY REPORT ON FORM 10-Q FOR THE FISCAL QUARTER ENDED MARCH 31, 1998 OF
MAHASKA INVESTMENT COMPANY AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH
FINANCIAL STATEMENTS.
</LEGEND>
<MULTIPLIER> 1,000
       
<S>                             <C>                         <C>
<PERIOD-TYPE>                   3-MOS                       3-MOS
<FISCAL-YEAR-END>                          DEC-31-1998                 DEC-31-1997
<PERIOD-START>                             JAN-01-1998                 JAN-01-1997
<PERIOD-END>                               MAR-31-1998                 MAR-31-1997
<CASH>                                           9,254                      9,635
<INT-BEARING-DEPOSITS>                           4,429                      1,284
<FED-FUNDS-SOLD>                                12,273                          0
<TRADING-ASSETS>                                     0                          0
<INVESTMENTS-HELD-FOR-SALE>                          0                          0
<INVESTMENTS-CARRYING>                          18,321                     26,427
<INVESTMENTS-MARKET>                            18,387                     26,280
<LOANS>                                        146,999                    124,052
<ALLOWANCE>                                    (1,872)                    (1,578)
<TOTAL-ASSETS>                                 276,013                    254,946
<DEPOSITS>                                     218,529                    207,686
<SHORT-TERM>                                    16,550                      9,810
<LIABILITIES-OTHER>                              3,140                      2,657
<LONG-TERM>                                          0                          0
<PREFERRED-MANDATORY>                                0                          0
<PREFERRED>                                          0                          0
<COMMON>                                        19,038                     11,423
<OTHER-SE>                                      18,756                     23,370
<TOTAL-LIABILITIES-AND-EQUITY>                 276,013                    254,946
<INTEREST-LOAN>                                  3,400                      2,721
<INTEREST-INVEST>                                  622                        786
<INTEREST-OTHER>                                 2,612                      2,531
<INTEREST-TOTAL>                                 6,634                      6,038
<INTEREST-DEPOSIT>                               2,169                      2,029
<INTEREST-EXPENSE>                               2,512                      2,193
<INTEREST-INCOME-NET>                            4,122                      3,845
<LOAN-LOSSES>                                      110                        128
<SECURITIES-GAINS>                                  26                          0
<EXPENSE-OTHER>                                  2,207                      2,002
<INCOME-PRETAX>                                  2,246                      2,144
<INCOME-PRE-EXTRAORDINARY>                       1,430                      1,378
<EXTRAORDINARY>                                      0                          0
<CHANGES>                                            0                          0
<NET-INCOME>                                     1,430                      1,378
<EPS-PRIMARY>                                      .39                        .37
<EPS-DILUTED>                                      .37                        .36
<YIELD-ACTUAL>                                   10.80                      10.77
<LOANS-NON>                                        972                      1,031
<LOANS-PAST>                                       519                        199
<LOANS-TROUBLED>                                   351                        356
<LOANS-PROBLEM>                                      0                          0
<ALLOWANCE-OPEN>                                 1,816                      1,491
<CHARGE-OFFS>                                       64                         64
<RECOVERIES>                                        10                         23
<ALLOWANCE-CLOSE>                                1,872                      1,578
<ALLOWANCE-DOMESTIC>                             1,872                      1,578
<ALLOWANCE-FOREIGN>                                  0                          0
<ALLOWANCE-UNALLOCATED>                          1,872                      1,578
        

</TABLE>