Objectives Postoperative atrial fibrillation (AF) has been associated with less favorable outcomes in patients undergoing coronary artery bypass graft surgery (CABG) and may result in increased post-operative morbidity and mortality. A systematic review and meta-analysis of published studies was conducted to examine the risk factors of occurrence AF after CABG. Methods Using the Medline database, the Cochrane clinical trials database and online clinical trial databases, we reviewed all randomized controlled trials (RCTs) and observational studies examining the risk factors of occurrence of AF after CABG. We searched for literature published April 2009 or earlier. Results Our review identified 8 studies (observational studies), involving 14548 patients, that examined the risk factors of occurrence of AF after CABG. Although studies provide conflicting results, the overall outcomes suggests that advanced age, previous hypertension, numbers of bridge vessels may increase the occurrence of AF after CABG, while no significant difference of diabetes, preoperative myocardial infarction, and preoperative medication of β-Blocker have been observed between the AF patients and no-AF patients. Conclusions Patients with advanced age, previous hypertension and more numbers of bridge vessels had higher risk for the occurrence of AF after CABG, and perioperative medication and care must be intensified to decrease the postoperative occurrence of AF.