This study determined the effects of procedures designed to "enrich" the physical and social environment of an institutional ward on the "adaptive" and "maladaptive" child, adult, self, and object-directed behaviors of five profoundly retarded ambulatory females. Behavior observed in two treatment conditions, an environment "enriched" with toys and objects and an "enriched" environment coupled with differential reinforcement of adaptive behavior, was compared to behavior occurring in corresponding baseline or "austere" conditions and during a period of noncontingent reinforcement. The results generally revealed: (1) little change in adaptive and maladaptive child and adult-directed behavior across conditions, (2) an overall higher incidence of adaptive object-directed behavior and reduced self-directed maladaptive behavior in each treatment condition from that observed in corresponding control conditions, and (3) the use of an "enriched" environment and differential reinforcement of adaptive behavior resulted in maladaptive self-directed behavior being reduced and adaptive object-directed behavior being icreased beyond that observed in the "enriched" environment alone. These behavioral gains were largely maintained during a follow-up condition by continuing the "enriched" environment and transferring the responsibility for differential reinforcement to direct-care staff.