This retrospective study analyzed 6,229 patients who underwent isolated coronary artery bypass grafting (CABG) from 2015 to 2023 to determine the risk factors for postoperative atrial fibrillation (POAF). The incidence of POAF was 30.94%. Univariate analysis revealed factors such as age, hypertension, smoking, CPB time, and ejection fraction (EF) as significant. Multivariate analysis identified older age and low EF as independent risk factors for POAF.