Abstract Background Radiofrequency catheter ablation, a widely recognized therapeutic option for atrial fibrillation (AF) has limited success rate as it is influenced by several factors including duration of AF. Purpose We evaluated the ablation success in AF patients intervened early versus late in the disease course. Methods Consecutive AF patients undergoing their first catheter ablation in 2015–16 at our center were included in the analysis. Patients were classified into two groups based on the time to ablation after AF diagnosis; 1) early: ≤12 months and 2) late: >12 months. All received PV isolation plus isolation of posterior wall and superior vena cava. Additionally, in non-paroxysmal AF cases, non-PV triggers were identified with isoproterenol-challenge and ablated. Patients were prospectively followed up for 3 years with regular rhythm monitoring. Results A total of 752 and 1248 patients were included in the “early” and “late” group respectively. Baseline characteristics of the study population is provided in Table 1 A. At 4 years of follow-up, overall success rate off-antiarrhythmic drugs was significantly higher in the “early” group (65.4% vs 57%, p<0.001). After stratification by AF type, “early” group was still associated with significantly higher success rate compared to the “late” group (Table 1B). Conclusion In this large series with standardized ablation strategy, early intervention with catheter ablation was associated with higher success rate in all AF types. Funding Acknowledgement Type of funding sources: None. Table 1