Background: Retroperitoneal Hematoma (RPH) is one of the most serious complications after Intra-Aortic Balloon Pump (IABP) Insertion. Although advances in clinical experience regarding IABP Insertion have led to a decrease in vascular complications such as RPH, its rate has remained considerably high. Objectives: This study aimed to evaluate the factors predicting RPH following IABP Insertion site injury. Methods: This retrospective cohort study of 2508 patients undergoing off-pump Coronary Artery Bypass Graft (CABG) surgery over 4. 5 years allowed the identification and evaluation of all patients with RPH. The patients were divided into with RPH and without RPH groups. RPH prediction was analyzed by multivariate stepwise logistic regression analysis. SPSS, version 22 (SPSS Inc., Chicago, IL) was used for statistical analysis. Results: RPH developed in 16 patients (overall prevalence: 0. 63%), with the highest frequency in low ejection fraction patients (3%). Female gender, compartment syndrome, IABP Insertion site, preoperative Clopidogrel usage, use of post-operative inotropic drugs, and body surface area were the predictors of RPH in multivariate analysis. Moreover, in-hospital mortality was significantly higher in the patients who had developed RPH compared to those who had not (50% vs. 1. 9%, P = 0. 004). Conclusions: RPH is a serious vascular access site complication of IABP, which has been associated with high morbidity and mortality. The current study findings indicated that such factors as female gender, BSA, IABP Insertion site, preoperative Clopidogrel usage, IABP usage, and post-operative inotrope drugs use could predict RPH. Identification of RPH risk factors could in turn prevent this problem.