Neuropathological findings are reported in an adult with Gaucher's disease. In this patient, Gaucher cells with characteristic storage material were found throughout the brain and also in the leptomeninges. They were confined to the perivascular space of small blood vessels and were commonly associated with intense perivascular, glio-mesodermal fibrillary reaction. Neuronal storage was not seen. Glucosylceramidase activities were severely deficient in both brain and liver and glucosylceramide was abnormally increased in the liver of this patient. The significance of the neuropathological changes is briefly discussed.