<PAGE>

                                                                      EXHIBIT 21

                        ICF KAISER INTERNATIONAL, INC.
                   9300 Lee Highway, Fairfax, Virginia 22031
                                (703) 934-3600

     ICF Kaiser International, Inc.'s consolidated subsidiaries are listed
below.  Consolidated subsidiaries which are less than wholly owned are indicated
by the ownership percentage figure in parentheses following the name of the
consolidated subsidiary.

<TABLE>
<CAPTION>
                                                                                   Jurisdiction
Consolidated Subsidiary                                                            of Formation
-------------------------                                                         --------------
<S>                                                                                <C>
I.   Cygna Group, Inc.                                                                Delaware
     II.   Liability Risk Management, Inc.                                          California
I.   EDA, Incorporated                                                                Maryland
I.   HBG Hawaii, Inc.                                                                 Delaware
I.   HBG International, Inc.                                                          Delaware
I.   ICF Kaiser Development Corporation, Inc.                                         Delaware
     II.   Global Trade & Investment, Inc.                                            Delaware
I.   ICF Kaiser Engineers Group, Inc.                                                 Delaware
     II.   Henry J. Kaiser Company                                                      Nevada
     II.   ICF Kaiser Engineers, Inc.                                                     Ohio
           III.   Henry J. Kaiser Company (Canada) Ltd.                                 Canada
           III.   Kaiser Engineers & Builders, Inc.                                   Delaware
           III.   Kaiser Engineers (California) Corporation                           Delaware
           III.   Kaiser Engineers Corporation                                        New York
           III.   Kaiser Engineers of Michigan, Inc.                                  Michigan
           III.   ICF Kaiser International Planning & Design, Inc. (33 1/3%)      Pennsylvania
           III.   Kaiser Overseas Engineering, Inc.                                   Delaware
           III.   Kaiser Engineers Limited                                      United Kingdom
                  IV.   Kaiser Engineers Technical Services Limited (80%)               Cyprus
           III.   Kaiser Engineers and Constructors, Inc.                               Nevada
                  IV.   ICF Kaiser Engenharia e Participacoes Ltda. (99.9%)             Brazil
                        V.   ICF Kaiser Construcoes e Engenharia Ltda (99.989%)         Brazil
                  IV.   ICF Pty. Ltd. (50%)                                          Australia
                  IV.   Kaiser Engineers Limited (0.02%)                                  U.K.
                  IV.   Kaiser Engenharia S.A. (50%)                                  Portugal
                        V.   ICF Kaiser Construcoes e Engenharia Ltda (0.01%)           Brazil
                  IV.   Kaiser Engineers (NZ) Ltd (1%)                             New Zealand
                  IV.   Kaiser Engineers Pty. Ltd. (50%)                             Australia
                        V.   KWA Kenwalt (50%)                                       Australia
                        V.   ICF Kaiser Aluterv KFT                                    Hungary
                        V.   ICF Kaiser Engineers Asia Pacific Pty Ltd               Australia
                        V.   ICF Kaiser Engineers (Hong Kong) Ltd                    Hong Kong
                        V.   ICF Kaiser Engineers (Singapore) Pte Ltd                Singapore
                        V.   Kaiser Engineers (NZ) Limited (99%)                   New Zealand
           III.   Kaiser Engineers International, Inc.                                  Nevada
                  IV.   ICF Pty. Ltd. (50%)                                          Australia
                  IV.   ICF Kaiser Engenharia e Participacoes Ltda.(0.1%)               Brazil
                  IV.   ICF Kaiser Panama S.A.                                          Panama
                  IV.   Kaiser Engenharia S.A. (50%)                                  Portugal
</TABLE>
<PAGE>

<TABLE>
<S>                                                                                  <C>

                  IV.   Kaiser Engineers Pty. Ltd. (50%)                             Australia
           III.   Kaiser Engineers Limited (99.98%)                                       U.K.
                  IV.   Kaiser Engineers Technical Services Limited (80%)               Cyprus
                  IV.   Kaiser Engineers (UK) Limited (50%)                               U.K.
           III.   Kaiser Engineers (UK) Limited (50%)                                     U.K.
                  IV.   Kaiser Engineers Technical Services Limited (20%)               Cyprus
           III.   KE Services Corporation                                             Delaware
           III.   Kaiser Engenharia e Constructoes Limitada                             Brazil
     II.   International Waste Energy Systems, Inc.                                   Delaware
     II.   KE Livermore, Inc.                                                         Delaware
I.   Kaiser Engineers Massachusetts, Inc.                                             Delaware
I.   ICF Kaiser Engineers Pacific, Inc.                                                 Nevada
I.   Kaiser Europe, Inc.                                                              Delaware
I.   ICF Kaiser / Georgia Wilson, Inc.                                                Delaware
I.   Kaiser Government Programs, Inc.                                                 Delaware
     II.   Kaiser K-H Holdings, Inc.                                                  Delaware
           III.   Kaiser-Hill Company, LLC (50%)                                      Colorado
                  IV.   Kaiser-Hill Funding Company, L.L.C. (98%)                     Delaware
           III.   Kaiser-Hill Funding Company, L.L.C. (1%)                            Delaware
I.   Kaiser Hanford Company                                                           Delaware
I.   Kaiser Holdings Unlimited, Inc.                                                  Delaware
     II.   American Venture Investments Incorporated                                  Delaware
           III.   American Venture Holdings, Inc.                                     Delaware
     II.   Cygna Consulting Engineers and Project Management, Inc.                  California
     II.   Excell Development Construction, Inc.                                      Delaware
     II.   Kaiser DPI Holding Co., Inc.                                               Delaware
     II.   Kaiser Engineers Eastern Europe, Inc.                                      Delaware
           III.   ICF Kaiser Netherlands B.V. (10%)                                Netherlands
     II.   Kaiser Hunters Branch Leasing, Inc.                                        Delaware
     II.   ICF Kaiser Netherlands B.V. (90%)                                       Netherlands
     II.   Leasing Corporation, Inc.                                                  Delaware
I.   ICF Kaiser Servicios Ambientales, S.A. de C.V. (66 2/3%)                           Mexico
I.   Kaiser Technology Holdings, Inc.                                                 Delaware
     II.   ICF Kaiser Advanced Technology, Inc.                                          Idaho
           III.   ICF Kaiser Advanced Technology of New Mexico, Inc.                New Mexico
I.   Kaiser R G.P. No. 1, Inc.                                                        Delaware
I.   Monument Select Insurance Company                                                 Vermont
I.   Phase Linear Systems Incorporated                                                Delaware
I.   Tudor Engineering Company                                                        Delaware
</TABLE>