Abstract. Atrial fibrillation can be cured by focal application of RF energy in pulmonary vein (PV) foci, but the technique is limited by the difficulty in mapping the focus if the patient is in ongoing atrial fibrillation (AF). In our study we used, as proposed by Carlo Pappone, purely anatomic approach with 3D electroanatomical (EAM) guidance by CARTO system. A total of 58 patients (42 men and 16 women) 53+13, years old were referred for RF ablation becaus of recurent paroxysmal (82%) or permanent atrial fibrillation: 22% of them with diagnosis of IHD (8% post MI), 42% with hypertension, 4% with hypertrophic a 4% dilated cardiomyopathy. After completion of EAM of left atrium (both anatomical and voltage map, 379 + 156 points) and PV identification circumferential RF lesions were created at nearly 5 mm around ostia of each PV with the aim of disconnecting these veins from left atrium defined by a bipolar amplitude <0.1 mV inside the encircled lesion. In 21 patients procedure was performed during ongoing atrial fibrillation. Sinus rhythm was restored during RF application in 9 of 21 patients, in further 12 by DC cardioversion. Voltage map obtained after ablation procedure in all patients revealed areas of low voltage (electrical silence) not only around PVs ostia, but also at posterior aspect of left atrium. In 1 patient pericardial and in another one retroperitoneal effusions due to heparin induced thrombocytopenia were observed. Mean fluoroscopy time was 22.4 (11-41) min. During 3-18 months of follow-up 2 patients have permanent atrial fibrillation. Single, short lasting and spontaneously terminated episodes of atrial fibrillation were observed in 55% of patients 1 month after ablation and in only 40% after 3 months. At 6 months 77% of patients were free of symptomatic arrhythmia. In all but 3 patients the quality of life measured by SF36 and Brignole Atrial Fibrillation Symptom Check List Questionnaires improved substantially. In conclusion, circumferential pulmonary vein ablation using electroanatomical guidance by CARTO system during sinus rhythm and ongoing atrial fibrillation is safe and successful method to identify target sites for RF ablation to cure atrial fibrillation.