Background: Procedural termination of atrial fibrillation (AF) may be associated with a good long-term outcome in patients with persistent AF. Objective: To determine the characteristics of the patients who converted from AF to sinus rhythm (SR) or cavotricuspid-isthmus dependent atrial flutter (CTI-AFL) without transition to organized left atrial (LA) tachyarrhythmias during ablation. Methods and Results: Thirty-two consecutive patients (26 males, 60±10 years) with AF which lasted more than 3 months when undergoing a first ablation procedure were retrospectively studied. Sixty-eight percent of the patients had AF refractory to amiodarone or bepridil. Pulmonary vein (PV) isolation was initially performed, followed by linear ablation and complex-fractionated electrogram ablation until AF termination. The mean AF duration was 6.7±6.7 months (3–33). During ablation, 26 patients (81%) converted to SR and 6 (19%) to CTI-AFL. The AF termination sites were identified around the PVs (n=21), at the LA anterior septum (n=5), mitral annulus (n=3), LA roof (n=2), and the right atrium (n=1). The mean LA diameter was 42±5 mm and 84% of the patients had LA diameter <45 mm. Conclusion: The preferential AF termination site was around the PVs, followed by at the LA anterior septum. The majority of the patients with AF termination had normal to mild LA dilatation.