Seven patients [six women and one man] with obstruction of hepatic portion of inferior vena cava was operated on, from May, 1969 to January, 1985. Of seven patients, six were undergone corrective operation for IVC obstruction and another one was not operated because of far advanced liver cirrhosis. The occlusions were found at or close to the level of diaphragm and they were membranous or diffuse with or without thrombi. Most of their symptoms were referable to either inferior vena caval or hepatic venous obstruction and onset of the symptoms was usually gradual, beginning between the age of their thirties and forties. Most of the patients showed marked elevation of peripheral venous pressure of lower extremity [29-40 cm H2O] preoperatively, which decreased significantly after corrective operation [17-30 cm H2O]. Venous catheterization for pressure study and venography were essential for confirming the diagnosis. Of six cases, in which corrective operations were done, Transatrial membranotomy with or without IVC dilatation were performed in five cases [case 1, 2, 3, 5, 6], using cardiopulmonary bypass and in another one case, bypass operation between IVC, distal to obstruction, and RA was done using Dacron tube graft under the thoracoabdominal incision. All survived and their conditions were improved.