We describe six patients with non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). From 1990 to 2001, we treated 82 patients with NASH and observed six patients (three men and three women, aged 56-72 years) in this group who were referred with HCC or developed the complication during follow-up. In five of these six patients, NASH was associated with obesity (cases 3, 4 and 5), hyperlipidemia (case 5), or diabetes mellitus (cases 1, 3 and 6). We confirmed the presence of HCC by ultrasonography-guided tumor biopsy or surgery except in case 3 where we diagnosed the tumor by ultrasonography, computed tomography and selective hepatic arteriography. The carcinomas measured 1.5-6.0 cm in diameter and three were well differentiated. When HCC was diagnosed, cirrhosis was present in all instances. Four of the six tumor patients also had esophageal varices but only one patient had a history of variceal bleeding and ascites. Treatment of HCC consisted of surgery (cases 1 and 5), transcatheter arterial embolization or infusion and/or percutaneous ethanol injection (cases 2, 3, 4, and 6). In patients with NASH cirrhosis, the development of treatable HCC is sufficiently common to warrant regular screening for this grave complication.