Background: Coronary artery bypass grafting (CABG) combined with coronary endarterectomy (CE) can be associated with high operative mortality and morbidity. An intra-aortic balloon pump (IABP) has been the most widely used mechanical circulatory support device during perfusion treatment. However, the benefits of preoperative IABP in CABG combined with CE remain unknown. We conducted a retrospective observational study to evaluate the efficacy of preoperative IABP therapy in patients undergoing adjunctive right coronary artery (RCA) endarterectomy. Methods: Between May 2013 and May 2016, 120 patients undergoing off-pump coronary artery bypass grafting (OPCABG) with RCA endarterectomy who received preoperative IABP support (IABP group, n=56) or who did not receive preoperative IABP support (control group, n=64) were evaluated retrospectively. Results: Patients in the IABP group had a significantly lower mean preoperative ejection fraction and a significantly higher mean EuroSCORE (both <0.05). The incidence of inferior myocardial infarction (MI) was significantly lower in the IABP group than in the control group (3.6% vs 15.6%, RR = 0.23, 95% CI 0.05-1.00, p=0.03). Hospital mortality was similar in the two groups (3.6% vs 4.7%, RR= 0.76, 95% CI 0.13-4.40, p=0.76). There were no significant differences between the two groups with respect to the rates of prolonged ventilation, low cardiac output syndrome, renal failure requiring dialysis, re-operation for bleeding or IABP-related complications. Preoperative IABP may be a protective factor of inferior MI (HR = 0.031, 95% CI 0.004-0.211, p<0.001) Conclusions: The preoperative use of IABP could reduce the incidence of postoperative MI in patients undergoing CABG with CE and seemed to shift high-risk patients into a lower-risk category.