School-based clinics (SBCs) are comprehensive primary health care facilities located within or on the grounds of middle, junior, or senior high schools. Varying in size and organizational structure, SBCs have emerged as an effective model for advancing adolescent health. They have gained attention because of their potential for treating problems such as inadequate access to health care, unwanted pregnancy, premature parenting, early withdrawal from school, depression and stress, and substance abuse. While school-based health centers will not resolve all these complex problems, they are greatly needed because of economic factors limiting health care access and age-related factors related to adolescent growth and development, risk-taking behavior and violence, sexuality, and the psychological transition to adulthood. SBCs are proving successful because they are accessible and comprehensive, facilitate feedback and compliance, have community suport, deal with early and unprotected sexual activity, and involve parents. In fact, clinic staff work together with parents, school counselors, nurses, administrators, and community health care workers to solve teens' problems and help families function. This guide documents broad national support for the SBC concept, includes sample resolutions and policy statements, outlines background information on adolescents' health and the need for SBCs, and lists resources to provide a greater understanding of these clinics. (MLH)