Extrahepatic spread of hepatocellular carcinoma was investigated in twenty autopsy cases with unresected hepatocellular carcinoma to define the appropriate patient selection criteria for liver transplantation. Diagnosis of extrahepatic spread of cancer by diagnostic imaging was not easy, and unsatisfactory prognosis after liver transplantation in patients with hepatocellular carcinoma might have been attributed to the high incidence of extrahepatic occult foci of cancer. All patients with multiple nodular, massive and diffuse tumor had extrahepatic spread of cancer. Only patients with a single nodular type tumor, no larger than 30 mm in diameter, had no extrahepatic metastasis, and these patients are the preferred candidates for liver transplantation.