The clinical and pathologic features of two brothers with the adult form of Gaucher's disease, both of whom developed cerebral glioblastoma multiforme, are presented. Neither patient had a long-standing neurologic disorder, and morphologic evidence of nervous system glucocerebroside storage was not seen. Despite the known increased incidence of malignancy in Gaucher's disease, a review of the literature and of sixty-two Mayo Clinic cases of adult onset Gaucher's disease revealed only one other instance of the association with glioma. The significance of the relationship is unknown.