Fueled by demands for the reform of social and educational programs and pressured for solutions to increasing social problems among youth, school policy experts have turned to the promising effectiveness of school-based prevention programs. These programs often focus on preventing emotional and behavioral problems in children and adolescents. Schools represent a natural environment for prevention programs because most children attend schools and an infrastructure exists in schools for reaching large numbers of children during their formative years. The science of school-based prevention is reviewed by evaluating the impact of empirically evaluated programs. The focus is on how interventions have improved the behavioral, social, or academic adjustment of participants, apart from any changes that have occurred in information and beliefs. Programs are divided according to prevention goals, and procedures and outcomes of representative interventions in each area are presented. The most promising programs and strategies are highlighted, and unresolved issues are discussed. Additional information is appended on program data interpretation procedures. References, tables, and figures