Background. Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery, resulting in an increased risk of morbidity and longer hospital stay. Pharmacologic prophylaxis has been recommended to improve the outcome in patients at high risk of developing POAF after cardiac surgery. Several studies have applied the CHA 2 DS 2 -VASc (Congestive heart failure, Hypertension Age [ ‡65 [ 1 point, ‡75 [ 2 points], Diabetes, and Stroke/transient ischemic attack (2 points)vascular disease [peripheral arterial disease, previous myocardial infarction, aortic atheroma]) score in the risk stratification of POAF but yielded contradicting results. This study aims to determine the association between CHA 2 DS 2 -VASc score and POAF and further to explore its discriminative ability for the prediction of POAF.Methods. We systematically searched the Medline, Embase, Cochrane library, and other data sources with key terms "CHA 2 DS 2 -VASc," "atrial fibrillation," and "cardiac surgery." Studies designed for CHA 2 DS 2 -VASc score in stratifying the risks of POAF in patients undergoing cardiac surgery were included. Statistical analyses were performed with R 3.5.1 and STATA 13.0.Results. Seven hundred twenty-one studies were identified, of which 12 studies with 18,086 patients were finally included in our analysis. The CHA 2 DS 2 -VASc score was found to be an independent predictor of POAF after cardiac surgery (odds ratio, 1.46; 95% confidence interval [CI], 1.25-1.72) and exhibited a relatively strong specificity (0.70; 95% CI, 0.61-0.78) and sensitivity (0.72; 95% CI, 0.54-0.85) for predicting POAF. The bivariate model-based pooled area under the receiver operating curve was estimated to be 0.76 (95% CI, 0.72-0.79).Conclusions. The CHA 2 DS 2 -VASc score has relatively good performance in predicting POAF after cardiac surgery and may help identify the patients at high risk of POAF.