<PAGE>
 
                                                                      EXHIBIT 21

                               PINKERTON'S. INC.
                             LIST OF SUBSIDIARIES

<TABLE> 
<CAPTION> 
                 NAME                                           STATE OR COUNTRY OF ORGANIZATION    
                 ----                                           --------------------------------              
<S>                                                             <C> 
Alarm Systems, Inc.                                                        Louisiana                          
Alertline Limited                                                        United Kingdom                       
Business Risks International (Europe) Limited                            United Kingdom                       
Delta Audio Visual Security, Inc.                                          Louisiana                          
Delta Audio Visual of Texas, Inc.                                            Texas                            
Delta Countermeasures, Inc.                                                Louisiana                          
Distribution Associates South, Inc.                                         Georgia                           
Douglas Roesch Communications, Inc.                                        California                         
Guardian Uniforms, Inc.                                                    California                         
J.L. Torbeck Co.                                                              Ohio                            
Judicial Services Limited                                                United Kingdom                       
Omega Corporation                                                          California                         
Pinkerton (Asia) Limited                                             British Virgin Islands                   
Pinkerton (Australia) Pty. Ltd.                                            Australia                          
Pinkerton Aviation Security Limited                                      United Kingdom                       
Pinkerton's of Canada Limited                                                Canada                           
Pinkerton (China) Limited                                                  Hong Kong                          
Pinkerton Consulting (M) Sdn Bhd (49% owned)                                Malaysia                          
Pinkerton Consulting Services (Taiwan) Ltd.                                  Taiwan                           
Pinkerton Court Escort Services Limited                                  United Kingdom                       
Pinkerton C.R. s.r.o                                                     Czech Republic                       
Pinkerton's du Quebec Limitee                                                Canada                           
Pinkerton (Far East) Inc.                                                 Philippines                         
Pinkerton Government Services, Inc.                                         Delaware                          
Pinkerton GmbH Holding                                                      Germany                           
Pinkerton (Hong Kong) Limited                                              Hong Kong                          
Pinkerton Insurance Company, Inc.                                          Tennessee                          
Pinkerton Investigation Services Limited                                 United Kingdom                       
Pinkerton Korea Limited                                                      Korea                            
Pinkerton Management Corporation                                           California                         
Pinkerton North Atlantic Limited                                         United Kingdom                       
Pinkerton Protection Services, L.P.                                         Indiana                           
Pinkerton Security Service GmbH                                             Germany                           
Pinkerton Security Services Limited                                      United Kingdom                       
Pinkerton Security Services (Guernsey) Limited                           United Kingdom                       
Pinkerton Security Services                                                 Ireland                           
 (Ireland), Ltd. (50% owned)                                                                                  
Pinkerton Security Systems, Inc.                                           California                         
Pinkerton Service Corporation                                              California                         
Pinkerton Servicios de Investigacao E Seguranca, Lda.                       Portugal                          
Pinkerton's Servicios de Seguridad Privada, S.A. de C.V.                     Mexico                           
Pinkerton (Singapore) Pte Ltd.                                             Singapore                          
Pinkerton Slovakia s.r.o.                                                   Slovakia                           
</TABLE>
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                               PINKERTON'S. INC.
                             LIST OF SUBSIDIARIES
                                  (continued)
<TABLE>
<CAPTION>
 
                 NAME                       STATE OR COUNTRY OF ORGANIZATION
                 ----                       --------------------------------
<S>                                         <C>
Pinkerton (Thailand) Limited                            Thailand
ProNet Image & Audio, Inc.                           North Carolina
P. T. Pinkerton Indonesia                              Indonesia
Signacon Controls, Inc.                                 New York
The Stanton Corporation                              North Carolina
Summons & Warrants (U.K.) Limited                    United Kingdom
Titan Security Services Inc.                            Michigan
WKD Security GmbH                                       Germany
WKD Pinkerton Security Services GmbH & Co. KG           Germany
Yeoman Security Group Limited                        United Kingdom
Yeoman Security Guards Limited                       United Kingdom
125129 Canada, Inc. (dba Canadalarm)                     Canada
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