The use of cyclazocine, a narcotic antagonist in the treatment of opiate addiction, is reviewed. Eleven investigations which have employed cyclazocine within addiction treatment programs have led to the conclusion that cyclazocine has yet to demonstrate its therapeutic efficacy due to low patient acceptance and the difficulty in maintaining effective blocking dosages. The use of naloxone to alleviate side effects during cyclazocine induction and technological advances in implantable sustained-release devices may facilitate the effectiveness of cyclazocine treatment of opiate addiction. Experimental designs are advocated as the best method for the evaluation of narcotic treatment programs.