A comprehensive mission for schools is to educate students to be knowledgeable, responsible, socially skilled, healthy, caring, and contributing citizens. This mission is supported by the growing number of school-based prevention and youth development programs. Yet, the current impact of these programs is limited because of insufficient coordination with other components of school operations and inattention to implementation and evaluation factors necessary for strong program impact and sustainability. Widespread implementation of beneficial prevention programming requires further development of research-based, comprehensive school reform models that improve social, health, and academic outcomes; educational policies that demand accountability for fostering children's full development; professional development that prepares and supports educators to implement programs effectively; and systematic monitoring and evaluation to guide school improvement.