Background: The values, perspectives, and behavior patterns that begin in adolescence can continue throughout one's life. Because of these lifetime effects, much research has focused on adolescent risk and prevention, but a new body of knowledge investigates protective factors and strengths. Positive youth development (PYD) increases internal and external assets during adolescence and is often based within communities. This review, however, focuses on school-based PYD interventions because these institutions are the largest youth-serving institutions in the country. Methods: This review considered 711 PYD school-based programs found using 4 databases. We included articles published after 2000, and did not review those reporting on regular school curriculum or activities. Results: The 24 remaining articles describe PYD programs that fall under 3 general categories: curriculum-based, leadership development, and student-based mentorship programs. Conclusions: Evaluations indicate that programs increase intrapsychic measures of well-being in youth as well as social confidence and healthy behaviors. However, it is important to not only include "at-risk" persons in programming, because a mixed group of young people encourages a more positive peer-to-peer climate. In addition, peer mentorship activities should be actively facilitated by an adult supervisor to ensure positive communication and trust between the mentor and mentee.