Considerable difficulties have been encountered in the residential treatment of adolescents with psychiatric disorders. Few of these programs have been successful. This study describes the long term effectiveness of a residential treatment program for disturbed adolescents. This program was particularly successful in returning severely disturbed adolescents to the community. None of the adolescents needed intensive residential treatment during the follow-up period. Three objective measures (Global Assessment Scale, Level of Functioning Scale, Adolescent Functioning Scale) were used at three specific times (admission, discharge and long term follow-up) to determine the level of psychosocial functioning of each adolescent. A significant improvement was found in the adolescents' level of functioning. These treatment gains were maintained at the time of long term follow-up (one to three years).