Introduction. Extracorporeal circulation (ECC) related systemic oxidative stress is a well-known entity but the underlying mechanisms are not clearly described. Our aim was to investigate the relation between the oxidative stress indices, inflammatory markers, and phosphorylcholine-coated (PCC) ECC systems. Patients andMethods. Thirty-two consecutive coronary artery bypass grafting (CABG) cases were randomly assigned to Group I (PCC, n = 18) and Group II (noncoated, n = 14) ECC circuits. Total Antioxidant Status (TAS), Total Oxidant Status (TOS), Tumor Necrosis Factor-alpha (TNF-alpha), Interleukin-1 beta (IL-beta), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), and Procalcitonin (PCT) levels were measured at 5 different time points. The association between the oxidative indices levels and PCC system used was analyzed. Results. In Group I TOS and TAS statuses were increased at T1, T2, T3, and T4, while IL-10 and TNF-alpha levels accompanied those raises only atp 2 (Group I-Group II, 4.73 +/- 2.04 versus 2.79 +/- 0.63, p = 0.002, and 30.56 +/- 8.11 versus 23.97 7.8, p = 0.031, resp.). In contrast, mean TAS and TOS levels were similar to baseline at all time points in Group II but IL-6 and IL-8 levels were increased atp 2 (Group I-Group II, 16.84 +/- 5.63 versus 44.81 +/- 17.0, p = 0.001, and 38.88 +/- 9.8 versus 46.14 +/- 9.25, p = 0.038, resp.). Conclusion. Even coated ECC systems are still incapable of attenuating the inflammatory response to cardiopulmonary bypass (CPB).