Background: Long stays in the Intensive Care Unit (ICU) following coronary artery bypass graft (CABG) surgery are associated with higher hospital mortality, poor long-term prognosis, prolonged hospital admissions, and consequently, excessive cost and resource use. This study aimed to identify the individual and perioperative risk factors influencing ICU length of stay after coronary artery bypass graft surgery at Azadi Heart Center in Duhok city. Patients and Methods: This comparative cross-sectional study reviewed the medical records of 230 patients who underwent CABG surgery from 1st January 2019 to 31st December 2020. The patients were divided into two groups based on their length of stay in the ICU. The usual stay group (ICU length of stay < 72 h), and the prolonged stay group (ICU length of stay ≥ 72 h). Results: Among the 230 patients studied, 53 (23.04%) patients had an ICU length of stay ≥ 72 hours and 177 (76.96%) patients had an ICU length of stay < 72 hours and the mean duration of ICU stay was 2.45 days, ranging from 1 to 13 days. This study found that the factors increasing the ICU length of stay after CABG were; preoperative myocardial infarction (MI), elevated preoperative WBC counts, prolonged cardiopulmonary bypass (CPB) time, prolonged intubation, reintubation, reoperation, readmission, arrhythmia, receiving inotropic agents in the ICU, cardiac, pulmonary, and wound complications, and a higher postoperative troponin level. Conclusion: This study showed pre-, intra-, and post-operative clinical and surgical risk factors affect prolonged ICU stays.