Many programs have been developed to help schools enhance students' health and reduce the prevalence of drug use, violence, and high-risk sexual behaviors. How should educators choose among these? This article describes selection criteria based on theory, research, and best educational practice that identify key social and emotional learning (SEL) competencies and program features. The SEL competencies for students include 17 skills and attitudes organized into four groups: awareness of self and others; positive attitudes and values; responsible decision making; and social interaction skills. The 11 program features critical to the success of school-based SEL programs emphasize curriculum design, coordination with larger systems, educator preparation and support, and program evaluation. Developed by the Collaborative to Advance Social and Emotional Learning (CASEL), the SEL framework can be used to guide selection of research-based prevention programs that address health, substance abuse, violence prevention, sexuality, character, and social skills.