Liver specimens from two patients with cerebrotendinous xanthomatosis revealed intracellular inclusions that appeared either as amorphous pigment or in a crystalloid form. The pigment was usually found in assoication with the smooth endoplasmic reticulum and occasionally free floating in the cytosol. The chemical nature of these inclusions has not yet been determined. However, the accumulation of such material may indicate the presence of nonmetabolizable bile alcohols resulting from a defect in bile acid synthesis.