Background: Atrial fibrillation (AF) is the most common arrhythmic complication after cardiac surgery.Several studies have compared the efficacy of landiolol and placebo or other agents in preventing new-onset AF in patients after cardiac surgery.In this study,we conducted a meta-analysis to determine whether landiolol is effective in preventing new-onset AF after cardiac surgery.Methods and Results: Five randomized controlled trials and two retrospective analyses were included in this study.The clinical outcomes of interest were the occurrence of AF after cardiac surgery and major complications.Meta-analysis was performed using RevMan 5.0.18 software,and pooled estimates of the effect were reported as risk ratios (RR) with 95% confidence intervals (CI).The results of this meta-analysis indicate that landiolol is significantly associated with a decreased risk of occurrence of AF after cardiac surgery (RR =0.33;95% CI: 0.23-0.48;P < 0.00001) and is not associated with an increased risk of major complications (RR =0.79;95% CI: 0.43-1.45;P =0.45) compared with the control group.Conclusion: Landiolol administration in the perioperative period can reduce the occurrence of AF after cardiac surgery without increasing the risk of major complications.It can be used to prevent new-onset AF safely after cardiac surgery.(PACE 2014;37:691-696).