Seventeen patients with ocular or oculodermal melanocytosis were identified among 1,250 Caucasian patients with uveal malignant melanoma. The uveal melanomas in these seventeen patients were similar in size, cell type, and tendency to metastasize to those occurring in reported populations without ocular or oculodermal melanocytosis. Clinical and histopathologic study of these 17 cases indicated that all of the affected eyes had episcleral and choroidal melanocytosis and that other ocular and periocular tissues (sclera, iris, conjunctiva, angle structures, and optic disc) were involved less commonly. The uveal malignant melanoma that was present in each of these cases involved the eye with melanocytosis. Furthermore, the melanoma arose from the zone of uveal melanocytosis in every eye with sectoral involvement. Statistical analysis of these data supports the contention that uveal malignant melanoma has a higher incidence in white persons with ocular or oculodermal melanocytosis than in those without these conditions.