OBJECTIVE To investigate the relationship among serum leptin, homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI) and dyslipidema in patients with nonalcoholic fatty liver disease (NAFLD). METHODS Eighty-two patients with NAFLD were divided into mild, moderate and severe NAFLD groups according histological examination results of the liver. Twenty healthy volunteers were chosen as the normal control (NC) group. Fasting insulin, glucose, leptin and lipid levels were measured in the 82 patients with NAFLD and the BMI calculated. IR index of the patients was calculated according to the HOMA method. RESULTS Leptin, HOMA-IR index, BMI and dyslipidemia showed significant differences between NAFLD and NC groups (P<0.05 or 0.01). Leptin and HOMA-IR index increased with the exacerbation of NAFLD, both of which were positively correlated with the severity of NAFLD. CONCLUSIONS Increased leptin level, HOMA-IR, BMI and dyslipidemia can be important risk factors of NAFLD, and serum leptin level and HOMA-IR are positively correlated with the severity of NAFLD.