Non-alcoholic fatty liver disease (NAFLD) comprises benign steatosis and steatohepatitis (NASH) and may lead to liver fibrosis, cirrhosis and hepatocellular carcinoma. Its prevalence is estimated to be 20% in the general population and 50-100% in patients with overweight and obesity. In about 15-30% of patients steatosis evolves to NASH which can only be diagnosed by means of a liver biopsy. NAFLD may be described as the hepatic component of the metabolic syndrome and is a consequence of the Western lifestyle. The pathogenesis is multifactorial; oxidative stress plays a crucial role in maintaining inflammation and progressive fibrosis. Lifestyle modification with weight loss and increased physical activity is the cornerstone of the treatment, which should take place in a multidisciplinary setting. To date, no specific registered drug for NAFLD treatment is available. Supportive drug therapy is mainly focused on aspects of the metabolic syndrome and chronic inflammation.