To examine whether or not being born in the southern United States is associated with an increased risk of ocular melanoma, the distribution of State of birth of 763 patients (White, not of Spanish origin) with ocular melanoma diagnosed between 1973 and 1984 and identified by 9 population-based cancer registries participating in the Surveillance, Epidemiology, and End Results program, was compared to the distribution of State of birth of the underlying population of the regions served by these registries. The incidence of ocular melanoma among persons born in the southern United States was nearly the same as that among persons born in the north, after adjustment for age, sex, and residence at diagnosis (Incidence Ratio = 1.1, 95% C.I. 0.8, 1.5). Comparisons of the risk of ocular melanoma between persons born in States with high and low levels of solar radiation yielded similar results, and a trend with increasing solar radiation was observed only among females. These findings do not support the hypothesis that exposure to the sun early in life is a major risk factor for ocular melanoma.