Twelve to 15 children with problem behaviors were enrolled in a demonstration head start class. The goals of the demonstration project were: (a) to provide remedial services for these children through the application of behavior modification procedures; (b) to provide head start teachers and related personnel with in-service training in behavior modification techniques; and (c) to conduct applied research based on the behavioral analyses of teacher-child interactions. Two case studies are presented. The first concerns an aggressively disruptive child, and the second, a child whose total behavioral repertoire consisted of bizarre and maladaptive behaviors.