Background: Obesity and its complications are global health concerns with rising interests, and in Bangladesh, the scenario is not different. This study was designed to analyze the effect of BMI on postoperative outcomes in patients who underwent Off-Pump Coronary Artery Bypass (OPCAB)graft surgery. Methods: This prospective observational study was conducted from September 2017 to August 2018 in the department of cardiac surgery, NICVD & 90 patients were divided into two groups. 43 patients in group A, with BMI ≥ 25 kg/m2 and 47 patients in group B, with BMI<25 kg/m2. Results: In between groups, homogenous distribution was noted in terms of age and sex. Pre-operative risk factors, such as hypertension, dyslipidemia, and sternal wound infection, harvest site infection along with post-operative AF, were significantly higher in group A in comparison to group B. Conclusion: Obese patients undergoing OPCAB surgery should undergo maximum care. Meticulous tissue handling during OPCAB surgery in obese patients is needed to avoid or minimize sternal, and harvest site wound infection.