Both segmental ostial and circumferential extraostial pulmonary vein (PV) isolation have been proven effective in the treatment of atrial fibrillation (AF). However, the recurrence of AF and PV conduction after the 2 ablation strategies has never been compared in a randomized study. A total of 100 consecutive patients (age 56 +/- 10; 71 men) with symptomatic AF (paroxysmal, 51; persistent, 49) were randomized to segmental ostial (n = 54) or circumferential extraostial (n = 46) PV isolation. A circular catheter positioned at the ostium of each target PV guided the ostial PV isolation. Extraostial PV isolation was performed by encircling the paired left and right PVs, respectively, guided by an electroanatomic mapping system. A total of 84% of the patients had recurrent AF after the first PV isolation procedure, showing 72% with AF and 12% with organized left atrial tachycardia. In patients undergoing reablation, all but 2 patients had recurrence of left atrium PV conduction (>95%). During a mean follow-up of 12 months without antiarrhythmic medication, 57% of patients who underwent extraostial PV isolation were free of arrhythmia symptoms compared with 31% of patients who underwent ostial PV isolation (P < .05). This difference in success rate between the 2 ablation strategies was mainly seen in patients known with persistent AF (52% and 15%, respectively; P = .02) as opposed to patients with paroxysmal AF (65% and 46%, respectively; P = .26). Overall, the more proximal, extraostial PV isolation was found to be superior to ostial PV isolation, especially in patients known with persistent AF. A high recurrence rate of 84% after a single complete PV isolation procedure was seen. At reablation, more than 95% had recurrence of left atrium PV conduction regardless of the procedure used, supporting the idea that complete PV isolation seems essential to prevent arrhythmia recurrences.