Background: The American Heart Association suggests considering amiodarone, sotalol, and/or β-blockers for the prevention of postoperative atrial fibrillation (POAF). However, managing POAF remains an area of uncertainty despite its high incidence and potential severity. While β-blockers are generally effective, their efficacy can vary due to class-related differences. We aim to conduct a systematic review and meta-analysis comparing two recommended β-blockers for the prevention of POAF.Methods: We searched PubMed/Medline, EMBASE, Web of Science, Scopus, and Cochrane Central for studies comparing metoprolol and carvedilol in the prevention of POAF in patients undergoing CABG. Primary outcome was to compare the incidence of POAF in two groups. The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) under the ID: CRD42023469364.Results: This meta-analysis included 691 patients across four clinical trials. The mean age of participants ranged from 5 ±10 to 63±9 years. Carvedilol was associated with a significantly lower incidence of POAF compared to metoprolol (RR: 0.628; 95% CI: 0.473-0.834, p<0.001). Risk difference analysis demonstrated a 13.95% absolute reduction in POAF with carvedilol (RD: -0.1395; 95% CI: -0.2 to -0.06). There were no significant differences between the groups in mortality (0.3% vs 0.7%), stroke (0% vs 0.3%), MI (0.3% vs 0.3%), or bradycardia (2.9% vs 3.3%) (all p>0.05).Conclusion: Carvedilol proves more effective than metoprolol in preventing POAF in CABG patients. Furthermore, patients on both β-blockers showed minimal mortality, low perioperative myocardial infarction, rare bradycardia incidents, and an infrequent need for electrical cardioversion.