We describe two boys in whom extensive normolipemic cutaneous papulonodular xanthomatous lesions developed and disabling central nervous system disease later developed. Histologically, lesional skin from each patient was consistent with juvenile xanthogranuloma. Electron microscopic studies in each case failed to reveal Langerhans (Birbeck) granules. Results of S-100 protein studies done with the peroxidase-immunoperoxidase technic were negative in each case. Radiation therapy and systemic corticosteroids have been partially successful in controlling the cerebellar ataxia experienced by one of the patients. The other patient had progressive central nervous system disease and died 8 years after the onset of his skin lesions despite radiation therapy and systemic chemotherapy. We believe that these cases are examples of normolipemic, xanthomatous, non-X histiocytosis with features of juvenile xanthogranuloma and aggressive central nervous system disease.