A dyadic behavioral intervention for children (ages 2 -7 years) and their parents or caregivers that focuses on decreasing externalizing child behavior problems (e.g., defiance, aggression), increasing child social skills and cooperation, and improving the parent-child attachment relationship. It teaches parents traditional play-therapy skills to use as social reinforcers of positive child behavior and traditional behavior management skills to decrease negative child behavior. Parents are taught and practice these skills with their child in a playroom while coached by a therapist. Coaching provides parents with immediate feedback on their use of the new parenting skills, which enables them to apply the skills correctly and master them rapidly. The therapy is time-unlimited; families remain in treatment until parents have demonstrated mastery of the treatment skills and rate their child’s behavior as within normal limits on a standardized measure of child behavior. Consequently, treatment length varies but averages about 14 weeks, with hour-long weekly sessions.