1 EXHIBIT 21 LIST OF SUBSIDIARIES OF CAPSTEAD MORTGAGE CORPORATION At December 31, 1999 the subsidiaries of Capstead Mortgage Corporation were as follows: STATE OF DOMICILE PARENT COMPANY SUBSIDIARY Capstead Mortgage Corporation ("CMC")......................................................... Maryland Capstead Advisers, Inc..................................................................... Nevada Capstead Capital Corporation............................................................... Delaware Capstead Select Corporation................................................................ Delaware Capstead Securities Corporation I.......................................................... Delaware Capstead Securities Corporation II......................................................... Delaware Capstead Securities Corporation III........................................................ Delaware Capstead Securities Corporation IV......................................................... Delaware CMC Securities Corporation I............................................................... Nevada CMC Securities Corporation III............................................................. Delaware CMC Securities Corporation IV.............................................................. Delaware CMC ARM Securities Corporation............................................................. Delaware Capstead Mortgage Services Corporation..................................................... Delaware Capstead Holdings, Inc.(1)................................................................. Delaware Capstead Inc.(2)........................................................................ Delaware CMC Securities Corporation II(2)........................................................ Delaware CMC Investment Partnership(3)................................................................. Texas (1) CMC owns all of the issued and outstanding preferred stock. (2) Capstead Holdings, Inc. owns all the issued and outstanding common stock. (3) A general partnership owned by CMC and Capstead Holdings, Inc.