The chemical composition of a brain from a child with the infantile form of Gaucher's disease has been studied. In cerebral regions the amounts of tissue lipids did not differ from those in control brains except in the temporal lobe, where a lower value of total lipids was found. In the brain stem the total tissue lipid fraction also was markedly diminished. Study of the hydrolysis products from glycolipids showed that glucose markedly exceeded galactose in the frontal lobe. Investigation of the hydrolysate of purified cerebrosides from this region indicated the glucocerebroside content exceeds that of the galactocerebroside. Ganglioside patterns of the cerebral regions and the cerebellum showed an increase of the monosialogangliosides GM1 and GM3.