Aggressive behavior and violence leading to disciplinary and legal difficulties have reached epidemic proportions among our youth. The severity of problems and social and economic costs to society have increased markedly. In this article, the authors review the risk factors, situational concerns, and warning signs that are important in predicting school violence and in designing effective prevention and early intervention efforts. They then describe programs with which they are involved as mental health professionals that appear to be extremely promising and applicable to other communities. The prevention and intervention programs are distinctive in that they involve collaborations with law enforcement, including the police and criminal sheriff, and the juvenile court as well as parents and schools in their efforts to promote positive development. These clinical, educational, and public policy approaches offer mental health professionals increased opportunities to be of help in this critical area.