This study aimed to evaluate the impact of left atrial appendage exclusion on clinical outcomes in patients with atrial fibrillation (AF) undergoing rheumatic mitral surgery.We retrospectively reviewed 1226 consecutive patients with AF (54.5±11.6 years; 68.2% females) who underwent rheumatic mitral valve (MV) surgery from 1997 to 2016. The left atrial appendage was preserved in 836 (68.2%) and excluded in 390 (31.8%) patients. Surgical AF ablation was performed in 506 (60.5%) and 304 (77.9%) patients with preserved and excluded left atrial appendage, respectively. For baseline adjustment, propensity matching was used.During a median follow-up of 63.4 months (IQRs, 20-111 months), there were no significant intergroup differences in the risks of mortality (2.77% vs 3.03%/patient-years) and thromboembolic events (0.91% vs 1.02%/patient-years). In the 258 pairs of propensity-score matched patients, death (2.77% vs 3.03%/patient-years) and thromboembolism (1.36% vs 0.82%/patient-years) outcomes were comparable for both groups. In a subgroup undergoing ablation (n=810), there were no significant differences in the adjusted risks of death (HR, 0.67; 95% CI, 0.34 to 1.32) and thromboembolism (HR, 0.47; 95% CI, 0.18 to 1.26). In a subgroup not undergoing ablation (n=416), however, left atrial appendage preservation tended to have higher adjusted risks for death (HR, 2.24; 95% CI, 0.98 to 5.13) and thromboembolism (HR, 4.41; 95% CI, 0.97 to 20.1).Left atrial appendage preservation did not seem to have greater risks of adverse clinical events in patients with AF undergoing rheumatic MV surgery particularly when ablation procedure is combined.