A woman with bilateral ocular melanocytosis developed a malignant melanoma of the choroid in one eye. The ocular melanotic hyperpigmentation, present since childhood, clinically involved the conjunctiva and episcleral and uveal tract of both eyes. To our knowledge this is only the second reported case of a uveal malignant melanoma in a patient with bilateral ocular melanocytosis. There is evidence that patients with ocular of oculodermal melanocytosis have an increased incidence of malignant melanoma of the uvea. It is possible that patients with bilateral ocular melanocytosis have a greater chance of developing of uveal malignant melanoma than do those with unilateral involvement.