The principal malignant melanocytic tumors of interest to ophthalmologists are those originating in the skin of the lids, the conjunctiva, and the uveal tract. Metastasis rarely, if ever, develops from melanocytomas of the optic nerve head, tumors of the pigmented epithelia, or primary melanomas of the orbit. Malignant melanomas of the lids and conjunctiva have many more features in common with those of the skin than with the more prevalent uveal melanomas. The most important of these are the tendency to metastasize via lymphatic channels to the regional lymph nodes and the frequent occurrence of metastatic disease at the time of initial presentation. In general, melanomas of all tissues carry a worse prognosis when they are large and/or thick, they exhibit deep invasion, they are of the epitheloid cell type, mitotic activity is marked, metastatic disease is evident, and the patient is older. Histogenetic classification of uveal melanomas has not been shown to be a useful guide to prognosis of patients with such lesions.