A school-based program called PeaceBuilders, designed for children in grades K-5, teaches ways to reduce aggression and hostility. Children learn to praise people, avoid put-downs, seek wise people as advisors and friends, notice and correct hurts they themselves cause, and right wrongs. The young students are given many opportunities to rehearse positive behavior and are rewarded for practicing such behavior. The article also describes Second Step, a school-based program where students learn empathy, impulse control, and anger management. Supporting Adolescents with Guidance and Employment (SAGE) focuses on African-American boys 12-16 years of age. That community-based program includes an 8-month African-American Rites of Passage section which includes adult mentoring, culture and history lessons and manhood and conflict-resolution training; a 6-week summer employment component; and a 12-week entrepreneurial experience. The article presents advice on developing a strategy to prevent youth violence and characteristics of promising school violence prevention programs.