A 63-year-old an developed fever and shock 2 weeks after undergoing a pancreaticoduodenectomy for carcinoma of the gallbladder with duodenal involvement. Computed tomography (CT) of the abdomen showed transient hepatic portal venous gas in the right lobe of the liver, which had probably been induced by obstruction of the bilioenteric anastomosis by the biliary drain. The gas and bacteria, both of which are commonly observed in cases of bilioenteric anastomosis, may have been diffused through the sinusoid into the portal venous system. Thus, hepatic portal venous gas could be a serious sign when it develops in patients with cholangitis following bilioenteric anastomosis.