Cutaneous melanoma is rapidly becoming a potentially curable cancer if it is detected and properly treated in an early phase of development. Unlike other cancers, which are usually hidden from detection until they are relatively large or metastatic disease has occurred, cutaneous melanoma is readily detectable simply by examining the skin. Information is now available that will be useful in selecting individuals at greatest risk. The most important melanoma risk factors (in decreasing order of importance) for a given individual are as follows: a persistently changed or changing mole, adulthood, irregular varieties of pigmented lesions (including dysplastic moles and lentigo maligna), a congenital mole, Caucasian race, a previous cutaneous melanoma, a family history of cutaneous melanoma, immunosuppression, sun sensitivity, and excessive sun exposure. Selective screening and appropriate treatment of individuals who have these risk factors may reduce the morbidity and mortality of cutaneous melanoma.