Background: When performing coronary artery bypass grafting (CABG) surgery, the utilization of cardiopulmonary bypass (CPB) is included, the rate of blood transfusions is higher than when off-pump CABG. (Few research, meanwhile, have explicitly looked at intraoperative hemodilution as a potential contributory factor. Aim: Examining the effects of off-pump coronary artery bypass grafting and cardiac pulmonary bypass grafting, two alternatives to traditional CABG, on postoperative hemorrhage and the need for RBC transfusions is the primary goal of this research. Patients and methods. Two hundred patients who had isolated coronary artery bypass graft (CABG) procedures performed by the Cardio-Thoracic Surgery Department at Benisuef University's Faculty of Medicine from August 2018 through September 2023 were the subjects of this retrospective study. Results: Statistical analysis including (age, sex distribution, BSA, and history of HTN and DM) demonstrated no statistically significant difference in demographics between the two groups. When comparing group 1 off-pump CABG to group on-pump CABG, our data indicated that there was a significant decrease in intensive care unit and hospital stays, with a p-value of less than 0.001. Furthermore, statistically insignificant differences were reported between both groups regarding the incidence of re-opening (4% in group 1 vs 5% in group 2), infection (3% vs. 4%), and mortality (1% vs 2 %). In conclusion, CPB does not operate as an independent variable that increases the likelihood of receiving more transfusions of blood and is not linked to heightened postoperative bleeding in cases of solitary CABG. Nevertheless, an elevated intraoperative hematocrit (Hct) level is linked to a decreased need for red blood cell (RBC) transfusions, a lower likelihood of reoperations due to bleeding, and decreased postoperative drainage. Effectively managing the dilution of blood during surgery is a critical consideration for minimizing problems associated with cardiopulmonary bypass.