Background. Cardiac revascularization on a beating heart avoids the side effects of cardiopulmonary bypass (eg, neurologic injury, hemodilution, and coagulopathy). We examined perioperative bleeding and use of blood products during coronary artery bypass grafting using either on-pump or off-pump techniques. Method. The charts of 126 patients who had coronary artery bypass grafting were reviewed. Data from 66 patients revascularized off pump and 60 patients with cardiopulmonary bypass (on pump) were analyzed using unpaired Student’s t test. Results. Average age was 62.5 years in either group. More patients received heparin preoperatively in the off-pump group that resulted in mild elevation of preoperative partial thromboplastin time and activated clotting time (40.4 ± 2.9 seconds and 150.1 ± 5.3 seconds, respectively). However, the off-pump group had less perioperative (intraoperative or postoperative) bleeding (2312 ± 212 mL versus 3251 ± 155 mL, p < 0.05) and required fewer blood products compared with the on-pump group. Hemoglobin and platelets decreased more in the conventional on-pump group. Conclusions. Avoiding cardiopulmonary bypass decreases perioperative bleeding and, consequently, reduces the use of blood products after coronary artery bypass grafting, which might result in fewer transfusion-related complications.