Dysplastic nevi are distinctive cutaneous nevomelanocytic lesions that can be recognized clinically and histologically. They were first described as markers of risk for melanoma in members of hereditary melanoma-prone kindreds. Subsequently, they have been discovered in a significant fraction of patients with sporadic melanoma, and in apparently normal members of the community. It is likely that they constitute markers of risk for melanoma in these populations as well, but that the risk is much less than in members of melanoma-prone kindreds. Beyond their role as risk markers, there is evidence that dysplastic nevi may act as precursors of some melanomas. Thus, their recognition offers an opportunity for analysis of pathogenetic mechanisms in cutaneous melanoma. Most dysplastic nevi, however, are completely stable over long periods of observation. Since up to 5% or even more of the population may bear one or more of these common lesions on their skin, it is important that the profession does not create an epidemic of cancer-phobia by over-emphasizing the significance of a dysplastic nevus. Patients with dysplastic nevi should adopt sensible patterns of skin care.