Atrial fibrillation (AF) is a common arrhythmia encountered after coronary artery bypass graft surgery (CABG) and is associated with poor outcomes. The purpose of this study was to examine whether initiation of statins before CABG reduces the risk of postoperative AF. We searched for clinical trials that randomized patients who underwent CABG to preoperative statin therapy versus placebo. We required that the trial reported the incidence of postoperative AF. Random-effects summary odds ratio (OR) were constructed. Sensitivity analysis for the trials that reported AF as a primary outcome along with subgroup analyses according to the different statins used was also conducted. Twelve trials with 2,980 patients met our inclusion criteria. Atorvastatin was tested in 8 trials, whereas rosuvastatin was studied in 2 studies. Statins were associated with a lower risk of postoperative AF (OR 0.42, 95% confidence interval [CI] 0.27 to 0.66, p <0.0001). There was benefit with atorvastatin (OR 0.35, 95% CI 0.25 to 0.50, p <0.0001) but not rosuvastatin (OR 0.69, 95% CI 0.28 to 1.71, p = 0.42). On sensitivity analysis limited to trials that reported AF as a primary outcome, the risk of postoperative AF was still reduced with statins (OR 0.40, 95% CI 0.25 to 0.90, p = 0.02). The mean duration of the hospital stay was significantly lower in the statin group: 8.5 ± 1.8 days versus 9.1 ± 2.2 days (p <0.0001). Statin therapy, particularly atorvastatin, before CABG was associated with a reduction in the risk of postoperative AF.