The development of postoperative atrial fibrillation (AF) is associated with surgical trauma, neutrophil activation, pro-inflammatory cytokine release and oxidative stress. Objective: assessment of the prognostic significance of determining blood oxidation rate in relation to the risk of developing atrial fibrillation in the postoperative period during coronary artery bypass surgery. Material and methods. The study included 68 patients with stable coronary heart disease (CHD) who underwent coronary artery bypass surgery under artificial circulation (On-pump), parallel artificial circulation and on the working heart (Off-pump). Indices of induced blood oxidation were studied using biological oxygen monitor, blood oxidation rate was determined. Results. It was found that within the factor model, the rate of blood oxidation is a significant (p < 0.05) component associated with the development of atrial fibrillation (r = 0.90) during surgical myocardial revascularization. According to the results of logistic regression analysis, it was found that the rate of blood oxidation affects the development of atrial fibrillation in the postoperative period of coronary bypass surgery. Conclusions. The rate of blood oxidation is a predictor of atrial fibrillation during coronary artery bypass surgery, regardless of the surgical procedure chosen.