A group of twelve adolescents exhibiting aggressive behavior in a residential treatment center received six weeks of anger control training consisting of thought stopping, relaxation training, and rehearsal of problem-solving, self-talk patterns. The subjects were divided into two groups, and a multiple baseline design was employed. Houseparents kept daily observational records of subjects' verbal and physical aggression. Both observational data and teacher ratings indicated that nine of the subjects reduced their rates of aggression. Two did not behave aggressively during the study period. One briefly deteriorated following a major disappointment, after which his aggression rate also declined.