Glucocerebroside levels were measured in the brains of patients with neuronopathic forms (types 2 and 3) of Gaucher disease and compared to those obtained from control brain. Nine separate brain regions (frontal, temporal, occipital, and cerebellar cortices; thalamus; corpus striatum; pons; medulla; and dentate nuclei) were analyzed. In all the Gaucher brains studied, the greatest glucocerebroside accumulation occurred within the occipital cortex, with lesser amounts in the temporal and frontal areas. The cerebellar cortex, corpus striatum, and thalamus in Gaucher brains had mildly increased levels of glucocerebroside, especially when the values were expressed as a percentage of total non-hydroxy fatty-acid cerebroside. Brainstem structures (pons and medulla) and dentate nuclei did not have increased glucocerebroside levels when compared to levels from similar control areas. However, when glucocerebroside concentration was expressed as a percentage of total non-hydroxy fatty-acid cerebroside, the type 2 Gaucher brainstem structures did show a slight increase in glucocerebroside levels over control levels. Neuropathological studies demonstrated the presence of Gaucher cells, gliosis, and microglial nodules within the type 2 brains. The neuropathological findings correlated with the glucocerebroside accumulation in the type 2 brains. Despite the similar pattern of glucocerebroside accumulation in the type 3 brain, no neuropathological abnormalities were seen. Thus, this study demonstrated that within several brain regions, both neuronopathic forms of Gaucher disease have elevated glucocerebroside levels, and that in the type 2 brains, the glucocerebroside accumulation correlated positively with the neuropathological findings.