Non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) are among the most common liver diseases. NAFLD with pure steatosis is considered benign. NASH, however, may progress to liver cirrhosis with risk of liver cancer. Therefore, it is important to search for treatment modalities for NASH. Because obesity and insulin resistance are risk factors for NASH, weight loss and exercise are considered mandatory, although limited data are in support. Presently, we focus on the prognosis of NAFLD and NASH and on pharmaceutical treatment, especially in the form of vitamin E and pioglitazone.