The document is intended as a practical reference to allow interested persons, agencies, and communities to make an informed decision about a program's appropriateness for their local situation, needs, and available resources. An introduction notes that demand for effective violence and crime prevention programs has never been greater, but most programs being used have not been evaluated. Therefore, a collaborative effort was conducted to identify 10 violence prevention programs that met a high scientific standard of program effectiveness, based on their strong research design, data indicating significant deterrent effects, sustained effects, and multiple site replication. The project included plans for a technical assistance and monitoring component. Multisystemic Therapy (MST) is an intensive family-based and community-based treatment that addresses the multiple determinants of serious antisocial behavior in juvenile offenders. MST targets chronic, violent, or drug-abusing male or female juvenile offenders who are ages 12-17 and at high risk of out-of-home placement. It also targets the offenders' families. MST uses a home-based model of services delivery to empower parents with skills and resources needed to address the difficulties that arise in raising teenagers and to empower youth to cope with family, peer, school, and neighborhood problems. MST has achieved favorable outcomes in rates of rearrest, out-of-home placements, family functioning, and mental health problems in serious juvenile offenders. Its costs are lower than the usual mental health and juvenile justice services. Figures, tables, appended program materials and replication descriptions, reference notes, and 84 references