An unusual combination of idiopathic superior and inferior vena caval obstruction occurred in a 15-yr. old boy. Portal hypertension with ascites and associated bleeding esophageal varices developed as a result of hepatic outflow obstruction due to the occluded inferior vena cava. Surgical decompression of the portal venous system was accomplished by splenectomy and placement of a Teflon tube graft between the splenic vein and the divided pulmonary artery to the left lower lobe, since the standard methods of creating an Eck fistula were not possible in this patient. The patient has experienced marked clinical improvement during the 9 months following operation.