Skin cancer is the most common type of cancer in the United States. Since 1973, new cases of the most serious form of skin cancer, melanoma, have increased approximately 150%. During the same period, deaths from melanoma have increased approximately 44%. Approximately 65%-90% of melanomas are caused by ultraviolet (UV) radiation. More than one half of a persons lifetime UV exposure occurs during childhood and adolescence because of more opportunities and time for exposure. Exposure to UV radiation during childhood plays a role in the future development of skin cancer. Persons with a history of > or = 1 blistering sunburns during childhood or adolescence are two times as likely to develop melanoma than those who did not have such exposures. Studies indicate that protection from UV exposure during childhood and adolescence reduces the risk for skin cancer. These studies support the need to protect young persons from the sun beginning at an early age. School staff can play a major role in protecting children and adolescents from UV exposure and the future development of skin cancer by instituting policies, environmental changes, and educational programs that can reduce skin cancer risks among young persons. This report reviews scientific literature regarding the rates, trends, causes, and prevention of skin cancer and presents guidelines for schools to implement a comprehensive approach to preventing skin cancer. Based on a review of research, theory, and current practice, these guidelines were developed by CDC in collaboration with specialists in dermatology, pediatrics, public health, and education; national, federal, state, and voluntary agencies; schools; and other organizations. Recommendations are included for schools to reduce skin cancer risks through policies; creation of physical, social, and organizational environments that facilitate protection from UV rays; education of young persons; professional development of staff involvement of families; health services; and program evaluation.