EXHIBIT 21.0 SUBSIDIARIES OF GALLAGHER In the following list of subsidiaries of Gallagher, those companies that are indented represent subsidiaries of the corporation under which they are indented. Except for directors' qualifying shares, 100% of the voting stock of each of the subsidiaries listed below, other than those indicated by footnote, is owned of record or beneficially by its indicated parent./(1)/ State or Other Jurisdiction of Name Incorporation - ---- ---------------- Arthur J. Gallagher & Co. (Registrant) Delaware Arthur J. Gallagher & Co. (Illinois) Illinois Arthur J. Gallagher & Co. of Oklahoma, Inc. Oklahoma Arthur J. Gallagher Risk Management Services, Inc. Illinois Arthur J. Gallagher & Co. of Wisconsin, Inc. Wisconsin Arthur J. Gallagher & Co. of Pennsylvania, Inc. Pennsylvania Gallagher Captive Services, Inc. Delaware Arthur J. Gallagher & Co.--Chicago Metro Illinois Arthur J. Gallagher & Co. (St. Louis) Delaware Gallagher Holt, Inc. Texas Arthur J. Gallagher, Inc. Texas Arthur J. Gallagher & Co. of Texas, Inc. Texas Arthur J. Gallagher & Co. (Florida) Florida Arthur J. Gallagher & Co. of New York, Inc. New York Colonial Alternative Risk Services, Inc. New York Arthur J. Gallagher & Co. Ohio Agency, Inc. Ohio Risk Placement Services, Inc. Illinois Risk Placement Services of Texas, Inc. Texas Risk Placement Services of Arkansas, Inc. Arkansas Risk Placement Insurance Services of Massachusetts, Inc. Massachusetts Risk Placement Services of Louisiana, Inc. Louisiana Risk Placement Services of Pennsylvania, Inc. Pennsylvania Arthur J. Gallagher & Co.--Greenville South Carolina Arthur J. Gallagher and Co. of Massachusetts, Inc. Massachusetts Gallagher Insurance Advisors, Inc. Massachusetts Arthur J. Gallagher & Co. of Rhode Island, Inc. Rhode Island Arthur J. Gallagher International, Inc. Delaware Arthur J. Gallagher & Co. (Bermuda) Limited Bermuda Arthur J. Gallagher Intermediaries (Bermuda) Limited Bermuda Arthur J. Gallagher Management (Bermuda) Limited Bermuda Gallagher Captive Services (Cayman) Limited Cayman Islands Scholastic Risk Services Limited Bermuda Artex Insurance Company Ltd/(2)/ Bermuda Artex Underwriting Managers Ltd Bermuda Protected Insurance Company Bermuda Arthur J. Gallagher & Co.--Little Rock Arkansas Arthur J. Gallagher & Co. of Georgia, Inc. Georgia Arthur J. Gallagher (UK) Limited England Risk Management Partners Ltd./(3)/ England John Plumer & Company Limited England Morgan Insurance Services Limited England MRS Holdings Limited England Morgan Read & Sharman Limited England Arthur J. Gallagher Asia Pte Ltd/(4)/ Singapore Arthur J. Gallagher Asia Limited Hong Kong 1 State or Other Jurisdiction of Name Incorporation - ---- ---------------- Gallagher Bassett Services, Inc. Delaware Gallagher Bassett of New York, Inc. New York Gallagher Bassett International Ltd. Delaware Gallagher Bassett International Ltd. (UK) England Gallagher Bassett Canada Inc. Canada Gallagher Benefit Administrators, Inc. Illinois Gallagher Bassett Investigative Services, Inc. Delaware Wyatt Gallagher Bassett Pty Ltd/(3)/ Australia Gallagher Bassett Australia Pty Ltd Australia Wyatt Gallagher Bassett (NSW) Ptd Ltd Australia Wyatt Group (PNG) Pty Ltd New Guinea Gallagher Bassett International S.A. France Arthur J. Gallagher & Co. Insurance Brokers of California, Inc. California Charity First Insurance Services, Inc. California Arthur J. Gallagher & Co. of Connecticut, Inc. Connecticut Craig M. Ferguson & Co., Inc. Connecticut C. W. Excess Incorporated New York Arthur J. Gallagher Intermediaries, Inc. New York Arthur J. Gallagher & Co.--Denver Colorado Arthur J. Gallagher & Co. of Michigan, Inc. Michigan Arthur J. Gallagher & Co. of Washington, Inc. Washington Gallagher Louisiana, Inc. Louisiana Arthur J. Gallagher of Louisiana, Inc. Louisiana Arthur J. Gallagher & Co. of Mississippi, Inc. Mississippi Arthur J. Gallagher & Co.--Kansas City, Inc. Missouri IMC Insurance Management Corporation Missouri IMC Services Corporation Missouri Arthur J. Gallagher & Co. of New Jersey, Inc. New Jersey Arthur J. Gallagher & Co. Ohio Life Agency, Inc. Ohio Gallagher Pipino, Inc. Ohio Arthur J. Gallagher & Co. of Minnesota, Inc. Minnesota Risk Placement Services of Arizona, Inc. Arizona AJG Financial Services, Inc. Delaware AJG Capital, Inc./(5)/ Illinois Aviacargo Leasing Limited Ireland AJG Investments, Inc. Delaware AJG Premium Finance, Inc. Illinois AJG Coal, Inc. Delaware Lamberson Koster & Company California Arthur J. Gallagher & Co. of Tennessee, Inc. Tennessee Arthur J. Gallagher & Co. of Kentucky, Inc. Kentucky Gallagher Benefit Services, Inc. Delaware Gallagher Benefit Services of Michigan, Inc. Michigan Gallagher Benefit Services of the Carolinas, Inc. North Carolina Gallagher Benefit Services of Colorado, Inc. Colorado Gallagher Benefit Services of Kansas City, Inc. Delaware Gallagher Benefit Services of New York, Inc. New York Gallagher Benefit Services of Texas, Inc. Texas Gallagher Benefit Services of Washington, D.C. Delaware GBS Retirement Services, Inc. New York Gallagher Benefit Services of Alabama Alabama GBS Insurance and Financial Services Delaware 2 State or Other Jurisdiction of Name Incorporation - ---- ---------------- Generation 2000 Loss Control Services, Inc. Tennessee Arthur J. Gallagher Service Company Delaware Arthur J. Gallagher Australasia Pty Ltd. Australia Arthur J. Gallagher Professional Services Australasia Pty Ltd Australia Arthur J. Gallagher Reinsurance Australasia Pty Ltd Australia AJG Two Pierce, Inc. Delaware John P. Woods Co., Inc. Delaware Gallagher Healthcare Insurance Services, Inc. Texas Gallagher Healthcare Insurance Services of Kansas City, LLC/(6)/ Missouri Specialty Catastrophe Services, Inc. New Jersey Manning & Smith Insurance, Inc. Kansas Arthur J. Gallagher & Co. of Iowa, Inc. Iowa (1) Gallagher conducts some of its operations under the following names: Gallagher Bassett Information Services, Gallagher Risk Management Services, Pacific Atlantic Administrators, The Boston Insurance Center, Gallagher Heffernan, Broussard, Bush & Hurst, Henley, Williams & Associates, Bryce Insurance, CMC Claims Management Corporation, Gallagher Byerly, Inc., Innovative Risk Services, Inc. and International Special Risk Services, Inc. (2) 76% of the Common Stock of this subsidiary is owned by two third parties. (3) 50% of the Common Stock of each of these subsidiaries is owned by an unrelated party. (4) 30% of the Common Stock of this subsidiary is owned by a third party. (5) 10% of the Common Stock of this subsidiary is owned by an unrelated party. (6) 49% of the Common Stock of this subsidiary is owned by a third party. 3