Introduction: Coronary artery bypass grafting (CABG) is one of the most common surgical methods in patients with coronary artery disease, a well-known complication of which is renal injury after surgery. Here we try to understand the factors involved in the incidence of acute renal injury in our patients. Objective: The present study aimed to evaluate the incidence and etiology of acute kidney injury (AKI) following CABG. Methods: This study was performed on 181 patients undergoing CABG surgery. The AKI was also recorded after registering demographic information and clinical indications. Chi-square, Mann-Whitney, and independent t-tests were used for data comparison. Results: The findings of our study pointed out that AKI following CABG in our patients was 3. 9% and showed no significant relationship with age, gender, hypertension, diabetes, type of surgery, hypercholesterolemia, number of clogged arteries, smoking, and length of surgery,however, blood urea was found to be significantly higher preoperatively in patients with AKI. Conclusion: As evidenced by the obtained results, AKI following CABG in the studied patients was 3. 9% and was not significantly associated with age, gender, hypertension, diabetes, type of surgery, hypercholesterolemia, number of clogged vessels, smoking, and the length of surgery. Nonetheless, urea was observed to be significantly higher in patients with AKI before surgery. Studies with larger sample sizes are recommended.