Non alcoholic fatty liver disease (NAFLD) is defined as fat accumulation exceeding 5% to 10% by the weight of the liver, in the absence of other causes of steatosis. NAFLD is strongly associated with metabolic diseases, such as metabolic syndrome. At present, insulin resistance, elevated concentrations of free fatty acids and oxidants, and an imbalance between different cytokines have been identified as the common pathophysiological elements underlying both NAFLD and metabolic syndrome. Emerging evidence also considers NAFLD as the hepatic manifestation of metabolic syndrome and supports a possible direct role of fat liver in cardiovascular risk assessment. Further investigations are needed to better understand the role of NAFLD, as an independent active factor in metabolic syndrome and associated cardiovascular disease.