Neurocutaneous melanosis is a very rare congenital syndrome characterized by the presence of large or multiple congenital melanocytic nevi and benign or malignant melanotic tumors of the central nervous system. We report herein a case of neurocutaneous melanosis with leptomeningeal melanosis and a malignant melanoma of the right temporal lobe in a 46-year old man. The case is exceptional as regards the late onset of symptoms and death. Even without a malignant melanoma, the symptomatic neurocutaneous melanosis has a fatal course. The syndrome is rare but lethal, so the dermatologist should be aware of this syndrome when evaluating the patients with large or numerous congenital melanocytic nevi so as to watch for the usual signs of increased intracranial pressure and to take prompt palliative measures.