Queensland has the highest incidence of cutaneous melanoma in the world, and the reported incidence has more than doubled in the last 15 years. The general geographical distribution of melanoma patients correlates negatively with latitude on a world scale. This suggests that exposure to solar ultraviolet rays is aetiologically important. The geographical distribution of melanoma patients in Queensland was examined by reviewing the residential addresses of all incident cases in a 12-month period from July 1, 1979, and no association with latitude was found. Rather there was a significantly increased incidence of melanoma in coastal, compared to inland, regions. When the distribution of doses of erythemal solar ultraviolet radiation in Queensland is examined, taking into account the effects of cloud cover, surface reflectance, and human behaviour, the observed regional differences in incidence may yet be explained by the variation in actual exposure to ultraviolet radiation received by the population.