Nonalcoholic steatohepatitis and chronic viral hepatitis C are the two dominant liver diseases in the Netherlands. Hepatic steatosis is usually innocuous but in twenty percent of patients it develops into steatohepatitis. One-fifth of these patients develop liver cirrhosis and hepatocellular carcinoma can also be a consequence of the disease. Nonalcoholic steatohepatitis is characterized by macrovesicular steatosis, necroinflammation, loss ofhepatocytes and fibrosis. Nonalcoholic steatohepatitis often is associated with type 2 diabetes mellitus, hypertension, dyslipoproteinemia and obesity. Insulin resistance plays a major role in the pathogenesis of this disease. Drugs against insulin resistance can ameliorate nonalcoholic steatohepatitis. Gradual weight loss, a diet including polyunsaturated fatty acids and exercise are other important treatment components of this condition.