Two cases of hepatic lymphangiomatosis were examined. One tumor was noted incidentally at autopsy, and the other tumor was removed by operation. These liver tumors could not be detected by the naked eye, but ill-defined lace-like areas were seen. Microscopically, small cystic spaces were irregularly aggregated in the hepatic parenchyma and, in part, in the portal tracts. Faintly stained lymph-like material without any erythrocytes was found in the spaces. The silver impregnation method confirmed that most of the cystic lumina were dilated Disse's spaces. Also, some of them were directly connected with lymph vessels in the portal tracts. Thin lining cells along the internal surface of these cystic channels could not be positively stained by Ulex europaens 1 or factor 8-related antigen, both of which were present in the endothelium of the blood vessels in the portal tracts. We describe herein this rare lymphangiomatosis of the liver, with special reference to its immunohistochemistry.