Background: Almost 30-65% of adult urban Indians are either overweight or obese or have abdominal obesity. The rising prevalence in India has a direct correlation with the increasing prevalence of obesity-related co-morbidities like hypertension metabolic syndrome dyslipidemia type 2 diabetes mellitus and cardiovascular disease. Aims and Objective: To compare oxidative stress parameters (superoxide dismutase (SOD) and plasma malondialdehyde (MDA)) in various grades of obesity. Materials and methods: This was a prospective randomized studydone in the Department of Medicine and Department of Biochemistry G. R. Medical College Gwalior. Patients were groped as Case (n=300 obese patients BMI > 25 kg/m2) and Control (n=100 age and sex matched healthy subjects having body mass index between 19-25 kg/m2). Complete physical examination along with lipid profile and fasting blood glucose was done for all the patients. Body mass index (BMI) was calculated as weight divided by height squared and was used to grade the obesity as Grade 1 obesity (25-29.9 Kg/m2) Grade 2 obesity (30 - 39.9 Kg/m2) and Grade 3 obesity (> 40 Kg/m2). Venous blood samples were obtained and were used for superoxide dismutase (SOD) and plasma malondialdehyde (MDA) determination. All the analysis was done with IMB SPSS ver. 20 software. Significance was assessed at 5 % level. Results: Mean age of patients among Case and Control groups was comparable (46.2 ± 2.4 vs. 44.5±2.2 years respectively) there was male predominance (61.33% and 54% respectively) (p> 0.05). Most of the patients had Grade 2 obesity (63.34%) followed by Grade 1 (27.66%) (p>0.001). Mean MDA level in Grade 1 and Grade 2 and Grade 3 obesity was 3.34±1.13 μmol/ml 4.81±1.04 μmol/ml and 6.63±1.21μmol/ml respectively whereas mean SOD activity was 9.54±1.45 units/ml 8.54±1.11 units/ml and 7.73±1.02 units/ml respectively. Males had low MDA and SOD levels compared to female. There was an inverse linear relationship between BMI and SOD level (n=300 r= -0.045 P<0.001) and linear relationship between BMI and MDA (n=300 r= 0.342 P<0.001). Conclusion: Obesity at any grade was associated with increase in MDA levels and reduction in SOD levels indicating the presence of oxidative stress due to the obesity itself in absence of any other disease.