Different techniques have been proposed to treat atrial fibrillation (AF) by catheter ablation. This study compares a new three-dimensional (3D) nonfluoroscopic navigation system with conventional fluoroscopy to guide pulmonary vein (PV) isolation. A total of 60 consecutive patients with paroxysmal or persistent AF were randomly assigned to 3D-guided ablation (group 1, n = 30), versus conventional fluoroscopy guidance ablation (group 2, n = 30). Complete PV isolation was achieved in both groups. The mean duration of fluoroscopy exposure (22 +/- 8 vs 56 +/- 10 minutes), and radiofrequency delivery (5 +/- 1 vs 10 +/- 3 minutes) were significantly shorter in group 1 than in group 2, P < 0.05 for both comparisons). The mean procedural time in group 1 was longer (225 +/- 15 minutes) than in group 2 (156 +/- 10 minutes, P < 0.05) due to the learning curve and time spent to generate the 3D maps. Over a mean follow-up of 7 +/- 2 months, 6 patients (20%) in group 2 had AF recurrences compared to 3 patients (10%) in group 1 (ns). The new nonfluoroscopic 3D system allows a high-resolution reconstruction of the left atrium and PVs. It significantly reduces the mean radiofrequency delivery and fluoroscopy times as opposed to ablation performed under fluoroscopy guidance.