Positive Youth Development (PYD) is a framework used to design and guide programs and services for children and youth. PYD emphasizes the relationship between young people's strengths and resources and their capacity to live healthy and productive lives. The underlying tenets of PYD suggest that healthy child and youth development is characterized by a sense of responsibility, connectedness, and positive values. Put into practice, key PYD strategies include identifying youth strengths, engaging and motivating young people to support positive growth through these strengths, working with youth as collaborators, and harnessing resources that exist in a young person's environment. PYD advocates assert that common risk-oriented prevention and intervention frameworks fail to consider the idea that preventing a problem from occurring does not guarantee that youth are developing and growing in a healthy manner. Thus, from a PYD perspective healthy development is not simply the absence of problem behavior but it also includes the cultivation of resources and strengths within a child and her or his particular context. Ultimately, PYD suggests that young people who have mutually beneficial relationships with other people and institutions will enter adulthood as positive and successful contributors. In this sense, individuals and their respective social ecologies-peers, schools, families, and communities-are active contributors to the developmental process and promotion of well-being. Today, on-the-ground proponents of PYD are social workers and other individuals who advocate for policy change and funding for interventions and community-based services aimed at promoting healthy youth development. The grassroots efforts of advocates and interdisciplinary research efforts of scholars have also contributed greatly to a recent proliferation in PYD programs for children and youth. The PYD model has much to offer practitioners, community and program planners, and administrators seeking to develop or improve interventions and program services for children and youth. The positive focus on healthy child and adolescent development that the framework embodies has stimulated a rapid increase in PYD programs since the turn of the 21st century. More important, positive outcomes garnered from participants of PYD programs have now begun to support the utility of the model in real-world contexts. Yet as the field has grown, so have challenges in characterizing what constitutes a PYD program, organization, policy, or set of practices.