The positive youth development (PYD) perspective is a strength-based conception of adolescence. Derived from developmental systems theory, the perspective stressed that PYD emerges when the potential plasticity of human development is aligned with developmental assets. The research reported in this special issue, which is derived from collaborations among multiple university and community-based laboratories, reflects and extends past theory and research by documenting empirically (a) the usefulness of applying this strength-based view of adolescent development within diverse youth and communities; (b) the adequacy of conceptualizing PYD through Five Cs (competence, confidence, connection, character, and caring); (c) the individual and ecological developmental assets associated with PYD; and (d) implications for community programs and social policies pertinent to youth.