Twenty-one patients with hepatocellular carcinoma (HCC) larger than 10 cm diameter were treated during the 18 year period from 197 1 to 1988. The mean tumor size was 13 cm (range 10-18 cm). Nineteen patients (90.5%) had subjective symptoms. Eight patients (38.1 %) had alpha-fetoprotein (AFP) levels over 10,000 ng/ml, and in 18 patients (85.7%) the levels were over 20 ng/ml. Nevertheless, only three (14.3%) were detected by AFP. Scintigraphy before 198 1 and ultrasonography after 1982 appears to be most helpful for detection of HCC. Nineteen lesions (90.5%) were localized in the right hepatic lobe. Large HCC showed a low incidence of histologically verified concomitant cirrhosis (33%; 7 of 21) and a relatively well preserved hepatocellular function (indocyanine green test; 13.9 k 6.6%). Curative resection could be done for all 21 patients. There were three (14.3%) operative deaths. The I-, 3-, and 5-year survival rates were 72.2, 32.9, and 8.2%, respectively. One patient who underwent a left hepatic lobectomy has survived for over 5 years, with recurrence. There were 14 recurrences (66.7%) in 21 patients: 11 were hepatic and three were in the lungs. In patients with large HCC, surgical resection should be done, provided the clinical status and hepatocellular reserves are adequate.