Operant conditioning, including a token economy, was used as a basis for structuring the milieu, 24 hours per day, for adolescent mental patients at a large urban state hospital. The home, the ward, and the Adolescent Service's central facilities (including schools and a varied program of activities) were coordinated in carrying out a consistent comprehensive treatment program. A psychoanalytic approach to diagnosis and to psychotherapy was also employed. When applied with an emphasis on clinical relevance by skilled clinicians, operant conditioning provided a useful complement to a more traditional orientation in planning individual treatment programs. Also it facilitated the use of other techniques, such as psychotherapy, and was in no way found to be incompatible with them in the treatment of this population. Illustrative case examples are given.