The aim of this study was to evaluate the variation in serum leptin levels in obese and non-obese type 2 diabetes mellitus (type 2 DM) patients and compared them with normal healthy controls. The study group consisted of forty patients of type 2 DM and twenty normal healthy controls. Blood glucose (FBS and PPBS), HbA1c, Serum lipids and lipoproteins, Serum leptin, and Body mass index (BMI) were estimated in obese and non-obese type 2 DM patients and normal healthy controls. The Mean±SD of serum leptin levels were significantly higher in obese (9.83± 1.72 ng/ml) and non-obese (6.09±1.83 ng/ml) type 2DM patients than normal healthy controls (5.38±2.20 ng/ml). BMI was found to be significantly higher in obese and non-obese patients than controls (28.1 ± 1.1, 23.5 ± 3.4 and 22.8 ± 2.3 respectively). Serum lipid and lipoprotein levels were observed to be significantly raised in patients of type 2 DM.The study concluded increased leptin levels were significantly correlated with high BMI (obesity) and type 2 DM. Hence increased levels of serum leptin can be used as risk factor in the development of type 2 DM.