Background & Objectives: Pure anatomical approach for circumferential pulmonary vein ablation (CPVA) or PV potentials (PVPs) guided ablation (electrical isolation) have been reported to be efficacious in curing atrial fibrillation (AF). The aim of this study was to prospectively compare the efficacy of CPVA + PVPs-guided isolation (PVPI) combined with additional elimination of residual potentials inside ablation lines with that of CPVA + PVPI only, in patients with paroxysmal (PAF) and persistent AF (PeAF). Methods: A total of 49 patients with a mean age of 55짹8 years who had PAF (n=28) and PeAF (21), refractory to more than 2 antiarrhythmic drugs, were randomly assigned to two different ablation approaches. One group received CPVA+PVPI+elimination of all residual potentials(>0.2 mV) inside circumferential lines (group A, n=24) and the other group had only CPVA+PVPI (group B, n=25). 3-dimensional NavX system was used for electro-anatomical guidance and 10-bipole ring catheter for recording of PVP at the each PV ostium. Results: There were no significant differences in the total procedure time (228짹73 min in group A vs. 226짹43 min in group B, NS) and fluoroscopic time (66짹21 min in group A vs. 65짹15 min in group B, NS). During a mean follow-up of 132짹31 days, only 1 patient in group A (4.2%, 1/24), but 5 patients in group B (20%, 5/25), recurred AF (p=0.05). In patients with PAF, AF did not recur among group A (0/15), but 2 from group B (15.4%, 2/13) recurred AF (p=NS). In patients with PeAF, AF recurrence rate was 11.2% (1/9) in group A and 25% (3/12) in group B, respectively (NS). Conclusions: CPVA+PVPI+elimination of residual potentials inside circumferential lines guided by voltage mapping led to better outcome than only CPVA+PVPI in patients with AF. The long-term efficacy rate of this approach with larger number of different subsets of AF needs to be further tested.