In two patients suffering from congenital oculodermal melanocytosis (nevus of Ota) orbital, osseous, meningeal, and cerebral manifestations are documented. In a 38-year-old European with a nevus of Ota on the right side an ipsilateral orbital tumor was diagnosed and surgically removed. The histological examination revealed a primary spindle shaped malignant melanoma of the orbit. In addition, many benign melanocytes were found in the optic nerve, in the extraocular muscles, in the orbital fat tissue, and in the dura of the sphenoid. In a 17-year-old Ethiopian with a nevus of Ota of the right side an increase in size of the pigmented process was observed during puberty in the orbital fat tissue, in the extraocular muscles, in the optic nerve, in the periorbital bones, in the temporal muscle, and in the cortex of the frontal brain lobe. A deep excision from the lower eye lid revealed a histologically benign oculo-orbito-dermal melanocytosis. An irradiation was performed because of growth again after segmental excision, however without success. In the ipsilateral eye a secondary open-angle glaucoma was diagnosed. In the nevus of Ota an involvement of the orbit and of the meningo-cerebral tissue must be considered.