Nine patients with hepatocellular carcinoma (HCC) in nonalcoholic steatohepatitis (NASH) (six men and three women, median age 71.5 years) and one patient with intrahepatic cholangiocarcinoma (ICC), a 50-year-old man, in NASH are described. Most patients were associated with obesity, diabetes, hypertension, hypercholesterolemia, or hypertriglyceridemia. Seven patients showed insulin resistance and hyperinsulinemia. All patients except one met the criteria for metabolic syndrome. An HCC or ICC diagnosis was confirmed by tumor biopsy, surgery or autopsy except in two patients, who were diagnosed by computed tomography or hepatic angiography. The underlying liver disease was liver cirrhosis in six patients and chronic liver disease including mild hepatic fibrosis in four patients. The treatment of liver cancers consisted of surgery, radio-frequency ablation (RFA), transcatheter arterial embolization and transcatheter arterial infusion. Although the follow-up period was relatively short (median 27.5 months, average 32.1 months), all postoperative and post-RFA patients have not had a recurrence of HCC to date, except for one patient who had a palliative operation with intra-arterial infusion of anticancer drugs through an implanted reservoir port. Older age and liver cirrhosis are considered risk factors for HCC in NASH, and regular screening of these patients is necessary. Diabetes may contribute to the development of ICC in NASH. Curative therapy (surgery or RFA) and weight loss by the active therapeutic intervention (nutritional care and exercise therapy) after curative therapy may help us improve the prognosis of HCC in NASH.