EXHIBIT 21.1 SUBSIDIARIES OF ADMINISTAFF, INC. - - Administaff of Texas, Inc., a Delaware corporation and wholly owned subsidiary of Administaff, Inc. - - Administaff Enterprises, Inc., a Texas corporation and wholly owned subsidiary of Administaff of Texas, Inc. - - Administaff Financial Management Services, Inc., a Delaware corporation and wholly owned subsidiary of Administaff of Texas, Inc. - - Administaff Partnerships Holding, Inc., a Delaware corporation and wholly owned subsidiary of Administaff of Texas, Inc. - - Administaff Captive Insurance Companies Limited, a Bermuda corporation and wholly owned subsidiary of Administaff Partnerships Holding, Inc. - - Administaff Retirement Services, L.P., a Delaware limited partnership, with Administaff of Texas, Inc. being a 1% general partner and Administaff Partnerships Holding, Inc. being a 99% limited partner. - - Administaff Services, L.P., a Delaware limited partnership, with Administaff of Texas, Inc. being a 1% general partner and Administaff Partnerships Holding, Inc. being a 99% limited partner. - - Administaff Partnerships Holding II, Inc., a Delaware corporation and wholly owned subsidiary of Administaff Services, L.P. - - Administaff GP, Inc., a Delaware corporation and wholly owned subsidiary of Administaff Services, L.P. - - Administaff Client Services, L.P., a Delaware limited partnership, with Administaff GP, Inc. being a 1% general partner and Administaff Partnerships Holding II, Inc. being a 99% limited partner. - - Administaff Companies, Inc., a Delaware corporation and wholly owned subsidiary of Administaff of Texas, Inc. - - Administaff Partnerships Holding III, Inc., a Delaware corporation and wholly owned subsidiary of Administaff Companies, Inc. - - Administaff Companies II, L.P., a Delaware limited partnership, with Administaff Companies, Inc. being a 1% general partner and Administaff Partnerships Holding III, Inc. being a 99% limited partner. - - Administaff Insurance Services, L.L.C., a Delaware limited liability corporation and wholly owned subsidiary of Administaff Companies II, L.P.