In an increasing number of U.S. communities, comprehensive health services--including family planning services--are being offered in clinics located in or near public high schools and junior high schools. Fourteen such programs operating in 32 schools are described here; they have caseloads ranging from about 500 to around 5,000 students per year and handle up to 20,000 patient visits annually. These clinics usually are staffed by teams consisting mainly of nurse practitioners, clinic aides and part-time physicians, as well as social workers, nutritionists and other professionals. Patients at school-based clinics generally are from low-income families, a reflection of the neighborhoods in which programs are located. Most school-based clinics serve only current students, but a few also serve former students. Most of these programs were originated by an individual from outside the school system. However, the cooperation and support of principals and teachers for student health services have been vital factors in gaining approval for in-school clinics. The programs also appear to enjoy the support of their local communities. However, their long-term funding remains uncertain. So far, private foundations have helped these programs become established, but they cannot be expected to provide continuing aid. Donations from schools, health providers and other groups have played an important part in keeping the cost of school-based programs low. Public funds, particularly from state departments of maternal and child health, social services and education, are being sought in order to expand existing programs to more schools and to start new clinics in other communities.(ABSTRACT TRUNCATED AT 250 WORDS)