Liver neoplasms, whether they are benign or malignant, are usually fed by the hepatic artery. We experienced a case of hepatic angiosarcoma supplied by both hepatic artery and portal vein. Since there are currently no specific laboratory tests to diagnose hepatic angiosarcoma, it is important to detect suspect cases from imaging features. This unique hemodynamic property was detected on computed tomography (CT) during hepatic arteriography and CT during hepatic arterioportography. If any imaging examinations indicate the liver tumor to be fed by the portal vein, hepatic angiosarcoma should be suspected.