Non-alcoholic fatty liver disease (NAFLD) is a condition associated with metabolic disturbances. The aim of the present study was to investigate the biochemical characteristics and risk factors for NAFLD. The study was carried out in a total of 881 subjects diagnosed by ultrasonography. NAFLD occurred mainly in middle-aged individuals, with a prevalence of 63.1 per cent. Multiple logistic regression analysis showed that male gender, presence of obesity, hypertension, dyslipidemia, or Type 2 diabetes and elevated serum alanine transaminase activities were independent risk factors for the development of NAFLD. Subjects with NAFLD were obese, hypertensive and often had signs of disturbances in lipid and glucose metabolism and abnormalities in hepatic functions. These findings show risk factors in the development and offer opportunities for prevention of NAFLD.