Abstract BACKGROUND: Leptin, the product of the ob gene, could have a role in the pathogenesis of obesity and non-insulin dependent diabetes mellitus (NIDDM). The aim of this study was to investigate relationships between serum leptin concentration and insulin, glucose, HbA1c levels and insulin resistance in diabetic women. METHODS: We studied 45 diabetic women and 45 healthy women (controls) who aged 45-60 years and had BMI of 25-30 kg/m2. Serum leptin, insulin, HbA1c, fasting blood sugar and insulin resistance were determined in the two groups. RESULTS: There was a significant positive correlation between leptin and insulin (r = 0.295, P = 0.049) and insulin resistance (r = 0.329, P = 0.027) in controls but non-significant correlation between leptin and HbA1c and fasting blood sugar were observed in the two groups. CONCLUSION: This study did not document any significant relationship between serum leptin and insulin, glucose, HbA1c and insulin resistance in diabetic women. Keywords: Type 2 Diabetes Mellitus, Leptin, Insulin.