Four related school-violence prevention models have been offered that apparently provide some focus and conceptual grounding. First, Hawkins, Catalano, et al., propose that prevention efforts promote the development of social bonding to school and academic success; promote school norms that are antithetical to violence; train students in nonviolent and conflict resolution; and minimize both the acceptance and use of firearms. Second, Samples and Aber (1998) argue for a developmental-contextual framework to shape violence-prevention initiatives in schools. Third, framing youth violence, including school violence, within a public health model has been advocated by a number of researchers or organizations. A fourth, closely related model brings together research in prevention science, risk-factors and protective-factors identification, and proactive education and training in prosocial competencies. This article's policy recommendations for the prevention of school violence are to use collaborative planning; to use data-based decision making and empirically supported programs and procedures; to develop a positive school climate and a sense of community; to involve a system for early identification and intervention; to incorporate schoolwide codes of conduct and schoolwide discipline plans; to target the needs of chronically aggressive students; to use schoolwide plans to prevent and manage serious incidents through security planning and crisis management; and to use research to test the effectiveness of programs across multiple contexts and populations. 144 references