A large kindred has two coexistent neurocutaneous syndromes: Certain members appear to have von Recklinghausen's neurofibromatosis (cutaneous neurofibromata, cafe-au-lait spots), others have von Hippel-Lindau's disease (angiomatosis retinae, renal cell carcinomas, pancreatic cysts), and at least one individual has a combined syndrome (neurofibromata, cafe-au-lait spots, pheochromocytomas, cerebellar hemangioblastoma, renal cell carcinoma, pancreatic cysts). Inheritance may be through either two separate genes segregating coincidentally in this family, or a unique single gene with pleiotropic expressivity.