Rates of recidivism among delinquents and relapse among adolescent drug abusers are high. Transition and aftercare services for drug-using juvenile delinquents are urgently needed. The pretreatment, during-treatment, and posttreatment factors that appear to be most important in predicting a return to drug abuse or crime include factors in the individual, peer group, family, school, and community. In addition, fixed pretreatment characteristics including face, offense, number of previous convictions, gender, low socioeconomic status, low IQ, and parent and sibling criminality also are associated with relapse and recidivism. A comprehensive approach is needed to rehabilitation that includes transition and aftercare services providing new opportunities to become involved in conventional life, assisting in developing new skills to interact with conventional others, supporting positive changes made during treatment, and dealing rapidly with relapse to drug use. The authors designed and tested an aftercare program, Project ADAPT, based on the hypotheses of the social development model and on what is known about factors related to relapse and recidivism. Project ADAPT's intervention approach combines behavioral skill training with supportive network development and involvement in social activities. Such a program may be an effective way to help adjudicated youths make successful transitions following treatment for drug abuse or delinquency. Figure and 89 reference notes