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. Big Brothers Big Sisters of America typically targets youth ages 6-18 from single-parent homes. Adult volunteers provide support and friendship to these youths in one-to-one relationships. Agencies use a case management approach. The case manager screens applicants, makes and supervises the matches, and closes the matches when eligibility requirements are no longer met or either party decides they can no longer participate fully in the relationship. An evaluation revealed that after 18 months, participating children were much less likely to initiate alcohol or drug use, had better academic performance and higher-quality relationships with parents and peers, and were less likely to hit someone than were control youth. Figures, tables, reference notes, appended reference information, and 60 references