Although it has been reported that pulmonary veins sometimes act as a focal driver of atrial fibrillation (AF), little has been reported concerning the contribution of the superior vena cava (SVC) to the maintenance of AF. Here we report a patient with sustained AF due to focal discharges inside the SVC after pulmonary vein isolation procedure. Stepwise radiofrequency current applications with the guide of multielectrode basket catheter mapping first disconnected the arrhythmogenic SVC from the right atrium and then eliminated the tachycardia.