This bulletin describes state-of-the-art universal and selective prevention programs designed to promote parent and teacher competencies and to prevent conduct problems. In addition, it describes indicated interventions designed for children who already have been diagnosed with oppositional defiant disorder and/or conduct disorder. Emphasis is placed on empirically supported programs that have identified key malleable risk factors in children, families, and schools, which have been shown in longitudinal research to be related to later development of substance abuse, delinquency, and violence. We have targeted preschool and primary grade chi ldren, ages 0-8 years, in this review because research suggests that the most effective interventions can nip in the bud risk behaviors in the early years, before antisocial behaviors become crystallized. Guidelines for selecting effective interventions are provided.