<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND> This schedule contains summary financial information extracted from
the Arthur J. Gallagher & Co. Financial Statements included in the Form 10-Q for
the nine-month period ended September 30, 2000 and is qualified in its entirety
by reference to such financial statements.
</LEGEND>
<RESTATED>
<MULTIPLIER> 1,000
<S> <C> <C>
<PERIOD-TYPE> 9-MOS 9-MOS
<FISCAL-YEAR-END> DEC-31-2000 DEC-31-1999
<PERIOD-START> JAN-01-2000 JAN-01-1999
<PERIOD-END> SEP-30-2000 SEP-30-1999
<CASH> 244,706 209,972
<SECURITIES> 59,878 61,715
<RECEIVABLES> 307,154 304,147
<ALLOWANCES> 867 930
<INVENTORY> 0 0
<CURRENT-ASSETS> 654,812 617,458
<PP&E> 122,217 121,272
<DEPRECIATION> 81,505 80,749
<TOTAL-ASSETS> 938,122 861,576
<CURRENT-LIABILITIES> 618,751 605,752
<BONDS> 0 0
0 0
0 0
<COMMON> 39,351 38,360
<OTHER-SE> 261,611 200,643
<TOTAL-LIABILITY-AND-EQUITY> 938,122 861,576
<SALES> 497,549 451,191
<TOTAL-REVENUES> 526,944 471,629
<CGS> 272,050 246,369
<TOTAL-COSTS> 272,050 246,369
<OTHER-EXPENSES> 159,305 146,001
<LOSS-PROVISION> 1,996 (497)
<INTEREST-EXPENSE> 496 1,181
<INCOME-PRETAX> 93,097 78,575
<INCOME-TAX> 30,722 27,325
<INCOME-CONTINUING> 62,375 51,250
<DISCONTINUED> 0 0
<EXTRAORDINARY> 0 0
<CHANGES> 0 0
<NET-INCOME> 62,375 51,250
<EPS-BASIC> 1.60 1.35
<EPS-DILUTED> 1.51 1.28
</TABLE>