Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of a metabolic syndrome, is a leading cause of chronic liver disease worldwide with prevalence 17-46 % in adult population. NAFLD is associated with type 2 diabetes, obesity and genetic factors and includes a spectrum of potentially progressive liver disease that comprises of simple steatosis, non-alcoholic steatohepatitis (NASH), variable degree of fibrosis and, ultimately, cirrhosis. Simple steatosis has been considered a benign condition, while the progression to fibrosis and advanced liver disease is related to NASH development. While steatosis is diagnosed by routine imaging methods, NASH could be diagnosed only by liver biopsy. Life style modification and weight reduction is the method of choice in the treatment of NAFLD. Despite intensive effort, no pharmacological treatment of NAFLD has been approved; based on the results of clinical trials the use of vitamin E or pioglitazone could be considered in the treatment of bioptically proved NASH. New antifibrotic and anti-inflammatory agents for the treatment of NASH are under evaluation. Recently, screening for NAFLD and/or advanced fibrosis in patients with type 2 diabetes has been advocated.