A persistent left superior vena cava (LSVC) is a common venous anomaly, occurring in up to 10% of patients with congenital heart defects. Usually, a LSVC drains into the coronary sinus, then to the right atrium. The LSVC can drain directly to the left atrium, resulting in a right-to-left shunt and systemic desaturation. Historically, surgery has been used to address this lesion. Transcatheter occlusion of the LSVC is an alternative to surgery. We report the novel use of the transseptal approach to access the LSVC, and device occlusion using the Amplatzer Vascular Plug-II. © 2013 Wiley Periodicals, Inc.