Group treatment is unique in that it offers the adolescent the chance to change while minimizing the threat to emerging identity. Group therapy developed during the 20th century, and the 1970's saw the emergence of group intervention models for a variety of patient and nonpatient populations. From the beginning it was seen as an efficient way of providing services to a relatively large number of patients. The three approaches to group treatment are the 'group as a whole' approach used as a training model, the 'individual in the group' approach focusing on psychodynamic work initiated by specific group members, and the 'freely interactive' approach using a variety of techniques. Group interventions with adolescents have used both behavioral and psychodynamic approaches and have occurred mainly in residential institutional settings. Therapists have come from many disciplines. Outcome studies have shifted their focus from whether group treatment works to the types of approaches that work for particular types of patients. The authors have had 2 years of experience with group therapy with aggressive adolescents in a public junior high school. The group goal was to teach social skills. The experience and the literature review indicate the desirability of the here-and-now focus, appreciation by the leaders of group dynamics, and the need for leaders to be involved in setting limits and in taking an active authority role. The importance of recognizing the larger system within which the therapy group always exists is also crucial. Forty-three references are listed.