The results of a two-year project designed to organize a unit for 18 developmentally disabled clients with severe behavior disorders (primarily aggression) were presented. Providing tightly organized structure and focusing on appropriate resident behavior resulted in substantial gains. Noted changes included significant decreases in aggression, total number of target behaviors, required uses of restrictive procedures, and residents' injuries. Decreases were also noted in staff injuries and turnover. Subjectively, the unit became a better place to work and live. Difficulties encountered with developing, maintaining, and generalizing the project were discussed.The treatment of severe behavior disorders has historically presented a great problem in institutions for persons with developmental disabilities. Even more so than severe physical handicaps, maladaptive behaviors tend to be the most frequently cited reason for denying community placement to these individuals (cf., Hill & Bruininks, 1984;Keys, Boroskin, & Ross, 1973;Lakin, Hill, Hauber, Bruininks, & Heal, 1983; Page1 & Whitling, 1978). Elimination, or even deceleration, of these behaviors is extremely difficult within the environment of the institution, where it is often this environment itself that has produced and reinforced the behavior. Further, individuals with severely disruptive behaviors, such as aggression, self-injurious behavior (SIB), pica, etc., frequently engage the attention of staff to the point of minimizing staff attention to residents ' The authors gratefully acknowledge the help and support of the many persons who contributed to the project described in this paper. Most notably, the responsible (and underpaid) staff who work directly with these subjects on a daily basis are commended for their dedication, compassion, and professionalism. These people are extraordinary in that their behavior appears to be reinforced by working with the Center's most difficult population. Also, the authors are indebted to JMH, for his role in the initiation of this project and for recognizing its potential, and to John Mabry, for his expert editing. Finally, this paper is dedicated to the subject population, whose progress reinforces our behavior.Requests for reprints may be directed to Alexander M. Myers, Ph.D.,