Hepatic portal venous gas is an uncommon clinical condition that is often characterized by acute onset of abdominal pain and is associated with a high rate of mortality despite clinical and/or surgical treatment. Radiologic diagnosis is important and usually includes abdominal radiography, ultrasound, and computed tomography. We describe the clinical, computed tomographic, and angiographic data of a patient with sigmoid diverticulitis who developed a massive embolism of the intra- and extrahepatic portal systems due to an enterovascular fistula and was treated with fistula embolization and subsequent sigmoidectomy.