Background: Contrast- enhanced three- dimensional rotational angiography (3DRA) is a novel method for three-dimensional reconstruction of the left atrium (LA) and pulmonary veins (PVs) during catheter ablation for atrial fibrillation (AF). The purpose of this study was to assess the feasibility and accuracy of anatomy obtained by 3DRA compared with cardiac computed tomography (CCT) and trans-thoracic echocardiography (TTE). Methods: Patients with an indication for AF ablation were included. Contrast enhanced CCT and TTE was performed within 24 hours prior to ablation. Intra-procedural 3DRA was performed with power injected contrast medium (20 cc per 1 sec for 4 sec, 240 angle) through a pigtail catheter. We compared circumferences of four PVs obtained from 3DRA and CCT and also compared LA volume measured by 3DRA, CCT and TTE (by prolate ellipse method). Results: Total 55 patients (mean age: 57.4 짹 9.5 year old) were prospectively included. Twenty six patients (47%) were paroxysmal, while 29 patients were persistent. The circumference of four PVs for 3DRA and CCT was well correlated in right superior PV (r = 0.50) and right inferior PV (r=0.57), respectively, (p<0.00), but was less in left superior PV (r = 0.33, p=0.04) and left inferior PV (r = 0.23, p=0.12). LA volume measured by 3DRA, CCT and TTE was 123 짹 32 ml, 113 짹 35 ml, and 59 짹 22 ml, respectively. The LA volume of 3DRA showed excellent correlation with that of CCT (r=0.81, p<0.00) and that of TTE (r=0.72, p<0.00) Conclusions: Intraprocedural imaging, 3DRA provides anatomical accuracy of LA and right side PVs comparable to those of cardiac CT, however, special attention is required to assess left side PVs using 3DRA. Also LA volume by 3DRA was well correlated with that of TTE, despite its absolute value was underestimated.