Background and Objectives: The performance of coronary bypass surgery without cardiopulmonary bypass ("off pump") may reduce perioperative morbidity and costs, but it is uncertain whether the outcome is similar to that involving the use of cardiopulmonary bypass ("on pump"). In fact, the advantage of using off-pump myocardial revascularization is being documented in high risk subgroups. Specific analysis performed in chronic pulmonary patients, elderly, and severe left ventricular dysfunction have demonstrated the advantage of using off-pump over on-pump myocardial revascularization. In light of these facts, our study is to compare on-pump versus off-pump myocardial revascularization in a specific population of low-risk patients and similar coronary artery disease. In this study on special subset of low risk patients, is off-pump procedure superior over conventional coronary artery surgery or not?Methods and Results: In a single-center randomized trial, 50 low-risk patients with multivessel disease requiring CABG surgery at a single institution were prospectively randomized to have the procedure performed with CPB (n_25) or on the beating heart (n_25). Exclusion criteria for the trial included emergency procedure, concomitant major cardiac procedures, poor ejection fraction or LVEF<30%, and reoperation. The mean number of grafts performed per patient (mean ± SD 3.5 ± 0.9 for the on-pump group and 3.2 ± 0.9 for the off-pump group) with no statistically significant difference between both groups (P value>0.05). No mortality was detected in both patient groups. Patients in the cardiopulmonary bypass group required significantly more blood transfusions (1.6 ± 1.1 units vs. 1.0 ± 0.8 units, P<0.05). There were no significant differences between the CPB group and the beating-heart group in perioperative myocardial infarction (4% on-pump versus 4% off-pump), permanent stroke (4% versus 0%; P>0.05), new atrial fibrillation (8% versus 4%; P>0.05), and superficial sternal wound infection (4% versus 4%). There were significant differences between the CPB group and the beating-heart group in The mean time to extubation (9.4 hours on-pump vs. 6 hours off-pump, P<0.05), the mean stay in the intensive care unit (44.6 hours on-pump vs. 37.4 hours off-pump, P<0.05), and the median length of hospitalization (11.3 days on-pump vs. 9.2 days off-pump, P<0.05).Conclusions: In low-risk patients, our findings suggest that excellent results can be obtained with both surgical approaches. The postoperative complications of both groups showed no statistically significant difference between the two groups. Ultimately, whether a patient benefits more from standard on-pump CABG or OPCAB may depend more on the familiarity, comfort, and skill of the individual surgeon with either procedure than on an intrinsic benefit.