We report the first four documented cases of childhood Niemann-Pick disease in Chinese. The clinical histories and biochemical, histopathological and ultrastructural findings are given. The four children born to consanguineous parents were from three families. Three of the four cases have features of Type A disease while the younger of the affected sisters, who had over 20% residual sphingomyelinase activity, was more typical of Type B disease. Post-mortem cultured fibroblasts, when compared to control fibroblasts, revealed early features of the disease at the ultrastructural level.