Although there can be no dispute that schools must do all that can be done to ensure the safety of learning environments, controversy has arisen about the use of zero tolerance policies and procedures to achieve those aims. In response to that controversy, and to assess the extent to which current practice benefits students and schools, the American Psychological Association convened a task force to evaluate the evidence and to make appropriate recommendations regarding zero tolerance policies and practices. An extensive review of the literature found that, despite a 20-year history of implementation, there are surprisingly few data that could directly test the assumptions of a zero tolerance approach to school discipline, and the data that are available tend to contradict those assumptions. Moreover, zero tolerance policies may negatively affect the relationship of education with juvenile justice and appear to conflict to some degree with current best knowledge concerning adolescent development. To address the needs of schools for discipline that can maintain school safety while maximizing student opportunity to learn, the report offers recommendations for both reforming zero tolerance where its implementation is necessary and for alternative practice to replace zero tolerance where a more appropriate approach is indicated. (Contains 2 figures.)