【Abstract】Objective To investigate the efficacy and safety of radiofrequency catheter ablation in the very old patients of atrial fibrillation (AF). Methods A total of 877 AF patients who underwent catheter ablation in our hospital from January 2008 to August 2014 were recruited in this study. According to their age, they were divided into very old group (≥75 years old, n=68), aged group (65-74 years old, n=320) and control group (<65 years old, n=489). The clinical data were collected and analyzed. The incidence of intra-operative complications, operation time, X-ray exposure time, post-operative thromboembolic rate, readmission rate, reoperation rate, post-operative administration rate of antiarrhythmia drugs and slow heart rate were compared among the groups. Successful ablation was defined as having no >30 s AF in any 24-hour holter monitoring during the follow-up period. SPSS statistics 19.0 was used to perform the statistical analysis. Chi-square test, analysis of variance, or LSD test was employed for different data types. Kaplan-Meier survival analysis was adopted to compare the success rate of ablation between the persistent AF and paroxysmal AF patients at different ages. Results In the evaluation of ablation procedure and safety, there were no significant differences in the incidence rates of complications (5.9% vs 3.1% vs 2.9%), operation time[(196.65±34.45) vs (196.03±40.02) vs (194.36±37.89) min] and X-ray exposure time[(19.81±6.73) vs (19.44±6.45) vs (18.69±6.00)min] among the 3 groups. After a mean follow-up period of (21.45±6.31) months, no obvious differences were found in the thromboembolism rate (4.4% vs 3.4% vs 2.5%), readmission rate (23.5% vs 22.2% vs 18.0%) and reoperation rate (11.8% vs 12.8% vs 12.3%) among the 3 groups. However, the very old group had lower rate of taking antiarrhythmic drugs (13.2% vs 29.4% vs 20.0%, P=0.001) and experienced higher rate of slow heart rate in holter monitoring (23.5% vs 15.6% vs 12.3%, P=0.033) than the other 2 groups. Kaplan-Meiers survival analysis indicated that there was no difference in the success rate of ablation between the persistent AF and paroxysmal AF patients at different ages. Conclusion The success rate and safety of catheter ablation are similar between the old and young AF patients.