The goal of this study is to improve the effectiveness of treatment of children referred for conduct disorder (aggressive and antisocial behavior). This goal is achieved by: 1) identifying key child, parent, and family domains that moderate the effectiveness of treatment, and 2) testing a new model of providing after-care once treatment is terminated. Child functioning and impairment, parent dysfunction and stress, and the ways in which families experience treatment are three domains that are predicted to moderate the effectiveness of treatment. The after-care program consists of systematically monitoring children and families and providing periodic treatment sessions, as needed. The purpose is to maintain treatment gains, to prevent relapse, and to reduce the need for and use of additional services following treatment. Children (N=160, ages 6-12) referred to outpatient treatment for conduct disorder will receive treatment, which includes the combination of problem-solving skills training and parent management training. After an initial treatment period, families will be randomly assigned to receive or not to receive a 12-month after-care program. The major predictions of the study are that: 1) responsiveness to treatment will be influenced by adversity in three domains (child dysfunction and impairment, parent dysfunction and stress, and barriers to participation in treatment); 2) children who receive the after-care program will show greater improvement than those who do not receive the program; 3) the benefits of after care will be reflected in improved parent and family functioning and reduced utilization of mental- and physical-health services; and 4) the impact of the after-care program will be particularly marked for the more severe and recalcitrant children, i.e., youth with greater adversity in the three domains. The study provides a model of care that has implications for delivery of services for children beyond the specific focus on conduct disorder.