Coronary artery bypass graft surgery (CABG) is one of the common treatments for cardiac diseases, despite the numerous complications of CABG. The most serious adverse events are bleeding requiring further surgery, cardiac arrhythmias, deep sternal wound infection and death. Aim of the study: This study was carried to examine postoperative complications in patients undergoing CABGs. Research design: this prospective observational study was conducted at CICU in Heart Assuit University Hospital. Methods: Data collected through a period of seven months, from first of August 2019 to the end of January 2020. At this period there were 68 patients admitted to Cardiothoracic department for CABG surgery, while 8 died and 60 patients included to the study. Three tools were used, Tool I: Cardiac surgical patient assessment sheet, Tool II: Predictors of mortality, and Tool III: CABG Complications sheet. Results: Findings of the present study revealed that patients post CABG surgeries in CICU reported several complications included: Atrial fibrillation (26.6%), Ventricular ectopic (8.3%), Ventricular tachycardia (1.6%), Cardiac tamponed (6.6%), while there were (10%) reported pneumonia, and (6.6%) reported atelectasis, about nausea (43.3%) and also (43.3%) reported vomiting complications, there was (20.0%) By acute kidney injury stage I, there was (5%) of patients complain from wound infection. Conclusion: the most complications occurred post CABG operations was Postoperative Atrial fibrillation (POAF), gastrointestinal complications, and acute kidney injury (AKI). Recommendations: Results of the study help in preoperative risk assessment, and understanding complications after CABGs.