Aim: Postoperative bleeding is a significant cause of morbidity and mortality in patients undergoing cardiac surgery. Studies have been conducted, and guidelines have been published regarding patient blood management and aiming to prevent blood loss in the perioperative period. Various bleeding risk assessments were developed for preoperative period. We aimed to examine the correlations of scoring systems in the literature with the amount of postoperative bleeding in patients undergoing first time coronary artery bypass graft surgery, and to show the most suitable preoperative bleeding risk assessment for coronary artery bypass graft patients. Methods: The study included 550 consecutive patients who underwent coronary artery bypass graft operation. The inclusion criteria were considered as patients to be older than 18 years old and to undergo elective or emergent myocardial revascularization using cardiopulmonary bypass. All variables required for scoring systems were recorded. The initial results of the study were determined as the amount of chest tube drainage, the use of blood products, the change in hematocrit level, reoperation due to bleeding, duration of ventilation, duration of intensive care unit stay, and hospital stay. Mortality which occurred during first 30 days after operation was considered as operative mortality. Operative mortality was accepted as the primary endpoint. Secondary endpoints were massive bleeding and high amount of transfusion. Results: Data were obtained from a series of 550 consecutive patients treated with isolated coronary artery bypass graft. It was seen that PAPWORTH and WILL-BLEED risk assessments responded better for E-CABG grade 2 and 3 bleeding compared to other risk assessments. TRACK, TRUST, and ACTA-PORT scales were found to have low ability to distinguish patients with E-CABG bleeding grade 2 and 3. Conclusion: Predicting postoperative bleeding and transfusion rates with preoperative risk scores in patients undergoing coronary artery bypass graft surgery will provide valuable information to physicians for establishing a proper patient blood management protocol and this will decrease excessive transfusions, unnecessary reoperations as well as improve postoperative outcomes.