Postmortem findings on a 12-year-old Flemish girl unexpectedly revealed a neurolipidosis with the biochemical features of Niemann-Pick disease (Crocker's group A). Three other siblings were similarly affected clinically. The late clinical onset was suggestive of Crocker's group C, but the huge amount of sphingomyelin and lysobisphosphatidic acid stored in the organs and in the brain gray matter and the pronounced deficiency of sphingomyelinase were pathognomonic of group A. Pathological findings were unusual too, since in addition to the lipid storage in most neurons and in the reticuloendothelial system, large amounts of lipopigment were found in glial cells from the pallidum, pars reticulata of the substantia nigra and dentate nuclei, thalamus, and brain cortex.