The effect of radiofrequency catheter ablation for atrial fibrillation (AF-ABL) has been established in the last decade and has become one of the major therapeutic options. As for the outcome of AF-ABL, there exit wide varieties in the success rate among the reports published so far, mainly due to the differences in the patient characteristics, ablation methods, and the observation manner/periods. In general, approximately 90% of success can be obtained in paroxysmal AF by a single procedure without the use of antiarrhythmic drugs, while it is around 60 to 80 % in persistent AF even with both repeat sessions and the use of drugs. The success rate has been shown to be constantly reduced during the long-term followup periods irrespective of the AF-type. Although AF-ABL has been shown to be effective to maintain sinus-rhythm compared to the pharmacological method, its impact on the prognosis has not been established yet.