The widespread implementation of effective prevention programs for children and youth is a sound investment in society's future. The most beneficial preventive interventions for young people involve coordinated, systemic efforts to enhance their social-emotional competence and health. The articles in this special issue propose standards for empirically supported programming worthy of dissemination and steps to integrate prevention science with practice. They highlight key research findings and common principles for effective programming across family, school, community, health care, and policy interventions and discuss their implications for practice. Recent advances in prevention research and growing support for evidence-based practice are encouraging developments that will increase the number of children and youth who succeed and contribute in school and life.