This study was designed to compare the effects of low doses of fentanyl with remifentanil on extubation time, hemodynamic changes, postoperative analgesic requirement and the duration of intensive care unit stay in patients undergoing coronary artery bypass grafting surgery. Forty patients, ASA physical status III-IV, were randomly and equally allocated to one of two groups. All of the patients received standardized anesthesia induction with etomidate and rocuronium. Anesthesia was maintained with sevoflurane along with remifentanil infusion in Group I and fentanyl infusion in Group II. The heart rates, systolic, diastolic and mean arterial pressures of the patients were recorded in preoperative, intraoperative and postoperative periods. Patients received intravenous morphine by patient controlled analgesia method and the Ramsey sedation scale, verbal pain scale, orientation scores, morphine consumption and total cost were evaluated in postoperative period. While changes in arterial pressures were insignificant in the remifentanyl group (p>0.05), heart rates were significantly higher than with the fentanyl group (p<0.05). Extubation time was shorter in the remifentanil group (p<0.05) Ramsey sedation scores, verbal pain scores, orientation scores and morphine consumption were similar in both groups (p>0.05). Fentanyl in small doses and remifentanil both provided good anesthetic depth, and hemodynamic stability in coronary artery bypass grafting operations. We concluded that remifentanil provided earlier extubation than fentanyl and there was no difference in cost.