Histochemical and electron microscopic examinations of the liver were performed in 5 adults receiving parenteral nutrition for greater than 18 mo and in 4 adults receiving parenteral nutrition for less than 5 mo. Phospholipidosis, reflected by the presence of cytoplasmic phospholipid deposits at histochemical examination and the presence of multilamellar lysosomes at electron microscopy, was marked and present in hepatocytes, Kupffer cells, and portal macrophages in all 5 patients receiving parenteral nutrition for greater than 18 mo. Mild phospholipidosis, affecting only hepatocytes, was demonstrated in 3 of the 4 patients receiving parenteral nutrition for less than 5 mo. These findings indicate that liver phospholipidosis is relatively common in patients receiving parenteral nutrition and that the degree of liver phospholipidosis depends on the duration of parenteral nutrition. Liver phospholipidosis might be due to intrahepatic accumulation of intravenous phospholipids provided by fat-emulsion sources.