Background/aim: Myocardial protection is an important factor of open heart surgery and biological biomarkers (lactate, CKMB, cardiac troponin I, and pyruvate) are used to assess myocardial damage. This study compares the effects of dexmedetomidine and remifentanil on myocardial protection during coronary artery bypass grafting (CABG) surgery. Materials and methods: Patients scheduled for elective CABG surgery (n = 60) were included in this study. Anesthesia induction was introduced with propofol, fentanyl, and vecuronium bromide. Anesthesia was maintained with remifentanil infusion and sevoflurane in the remifentanil group (Group R) and with dexmedetomidine infusion and sevoflurane in the dexmedetomidine group (Group D). Blood samples for biochemical markers were taken from the coronary sinus catheter before cardiopulmonary bypass (T1), 20 min after aortic cross-clamping (T2), 20 min after removal of the aortic cross-clamping (T3), and 10 min after separation from cardiopulmonary bypass (T4). Results: Demographic data were similar between the groups. Lactate level at the T2 period and CKMB levels during the study period were lower in Group D than in Group R. In both groups, all values except pyruvate significantly increased over time. Conclusion: The dexmedetomidine-sevoflurane combination may improve the cardioprotective effect in comparison with remifentanilsevoflurane in CABG surgery.