INFINITY PROPERTY AND CASUALTY CORPORATION EXHIBIT 21 - SUBSIDIARIES OF THE REGISTRANT The following is a list of subsidiaries of Infinity at December 31, 2003. All corporations are subsidiaries of Infinity and, if indented, subsidiaries of the company under which they are listed. Percentage of Name of Company Incorporated Ownership - -------------------------------------------------------- ------------ ------------- Atlanta Casualty Company Ohio 100 American Premier Insurance Company Indiana 100 Atlanta Reserve Insurance Company Ohio 100 Atlanta Specialty Insurance Company Ohio 100 Infinity Insurance Company Indiana 100 Infinity Agency of Texas, Inc. Texas 100 The Infinity Group, Inc. Indiana 100 Infinity National Insurance Company Indiana 100 Infinity Select Insurance Company Indiana 100 Leader Insurance Company Ohio 100 American Commonwealth Development Company Texas 100 Budget Insurance Premiums, Inc. Ohio 100 Leader Group, Inc. Ohio 100 Leader Managing General Agency, Inc. Texas 100 Transport Insurance Agency, Inc. Texas (a) Leader National Agency, Inc. Ohio 100 Leader Preferred Insurance Company Ohio 100 Leader Specialty Insurance Company Indiana 100 TICO Insurance Company Ohio 100 Windsor Insurance Company Indiana 100 American Deposit Insurance Company Oklahoma 100 Granite Finance Company, Inc. Texas 100 Coventry Insurance Company Ohio 100 Great Texas County Mutual Insurance Company Texas (a) Great American Contemporary Insurance Company Ohio 100 Infinity Property and Casualty Services Company, Inc. Georgia 100 Casualty Underwriters, Inc. Georgia 51 Dudley L. Moore Insurance, Inc. Louisiana 100 Hallmark General Insurance Agency, Inc. Oklahoma (a) Windsor Group, Inc. Georgia 100 Regal Insurance Company Indiana 100 Texas Windsor Group, Inc. Texas 100 (a) Denotes company which is affiliated but not owned