Purpose: Renal dysfunction remains a serious complication of coronary artery bypass grafting (CABG) surgery and is associated with increased mortality and morbidity. To date, a number of different strategies, including new pharmacologic agents, off-pump and cardiopulmonary bypass techniques have been used to avoid it, but none of them proves the excellent result. Methods: Between April 2009 to September 2011, 185 consecutive patients with multivessel coronary artery disease undergoing elective CABG were included the study. Iloprost was given with the onset of rewarming period at a dose of 1.25-2.5 ng/kg/min and it was ended together with the ending of CPB in 94 patients and remaining were in the control group. Creatinine clearance (CCr) and GFR were measured at the time of hospitalisation and on day first and fifth postoperatively. Serum potassium level was determined every 6 hours, during the first 24 hours postoperatively, and every 12 hours for the next 72 hours, and glomerular filtration rate was estimated. Results: There was no statistically significant difference in preoperative comorbidity. There were no significant differences in postoperative morbidity or mortality between either of the two groups that completed the study. However, urine output during the operation was significantly higher in the study group. An increase in creatine levels was more common in the control group. Development of a new CCr less than 50 ml/min was also significantly higher in the control group, postoperatively. Conclusion: Our study demonstrates that prophylactic intravenous iloprost administration after initiation of a rewarming period during CPB in patients undergoing CABG surgery is associated with improved renal function, compared with conventional treatment in wellhydrated patients. It also has a good safety profile and is generally well tolerated.