In this study, we attempted to determine the role of off-pump coronary artery bypass grafting (CABG) in the myocardial and systemic inflammatory responses. Twenty patients who underwent elective CABG were enrolled in this study. Ten patients underwent on-pump CABG, and 10 patients underwent off-pump CABG. There were no differences between patients in preoperative clinical variables. We took systemic venous blood samples for the measurement of tumor necrosis factor-alpha, the MB isoenzyme of creatine kinase (CK-MB), and cardiac troponin I, and we took myocardial biopsies from the interventricular septum for chemiluminescence assay of reactive oxygen species (hydroxyl, hydrogen peroxide, hypochlorite, and superoxide). There was no significant difference in the myocardial tissue release of hydrogen peroxide, hydroxyl, hypochlorite, and superoxide between the 2 groups (P > 0.05). The systemic tumor necrosis factor-alpha levels in the off-pump group were significantly lower than in the on-pump group (P <0.01). The cardiac troponin I and creatine kinase-MB levels at 6, 12, and 24 postoperative hours were not statistically different between the 2 groups (P >0.05). We conclude that off-pump CABG appears to reduce systemic inflammation, without reducing myocardial oxidative stress and inflammation.