We operated three cases of intrahepatic inferior vena caval obstruction from January, 1969 to February, 1978 at the department of Thoracic and Cardiovascular Surgery in Seoul National University Hospital. They were all female. And their ages were 33, 38 and 32 respectively. The lesions were the same site; just above the opening of the hepatic vein of inferior vena cava. In first case, segmental narrowing of the inferior vena cava without thrombosis was noted. In second case; thrombus occluded the inferior vena cava and left hepatic vein. In third case, we observed membrane of 4mm thickness which occluded the lumen completely. They were totally operated by using cardiopulmonary bypass. Their post-operative courses were good in the last two cases and re-obstruction was suspected in the first case.[KTCS 1978;2:161-164]