Background: Considering the effect of heart disease and its post-surgical complications on the patient's quality of life, identifying risk predictors for complications after surgery and the patient's clinical course can help us to improve the quality of primary care after surgery, reduce complications and improve the patient's recovery after surgery. This study aims to determine postoperative complication prevalence and related risk predictors. Material and methods: In this cross-sectional study, the clinical course after cardiac reoperation of patients in the cardiac operating room of Imam Khomeini Hospital during the years 2014-2021was studied. Patients who have had a stroke in the past six months, heart failure, and EF less than 25% were excluded from the study. This study investigates the relationship between preoperative and intraoperative conditions of patients (age, sex, hemoglobin, serum creatinine, blood product transfusion, and pump time) and postoperative complications (death, AKI, bleeding, CVA, and pulmonary complication. Results: This study examined 461 cardiac reoperation patients with a mean age (44.54±18.35). The most common complications were bleeding (8.24%), death (8.2%), and AKI (19.65$), respectively. In this study, there was a significant difference in terms of age, hemoglobin level, creatinine level, pump time, and blood product transfusion in patients faced with death and AKI compared to uncomplicated patients. Patients with postoperative bleeding received more blood products and had a longer pump time than uncomplicated patients, which was statistically significant. Conclusion: In this study, there was a significant difference between deceased and uncomplicated patients after cardiac reoperation in terms of age, anemia, pre operative renal failure, and receiving more blood products during surgery. This difference, however, does not necessarily create a causal relationship; but suggests some risk predictors for redo cardiac surgery.