Objectives: Over the last several decades, there has been drastic evolvement of transcatheter technology and remarkable changes in the therapeutic strategy of congenital heart disease (CHD) developed accordingly. Transcatheter techniques can also be helpful in the treatment of complex CHD in which surgery plays an exclusive role, as adjuvant measures throughout every stages of definitive palliation. We sought to reveal the role of transcatheter therapy in patients with functional single ventricle physiology. Methods: We investigated the frequency, timing, and details of transcatheter therapy in patients with functional single ventricle (FSV) physiology during 10-year period from January 2001 to August 2011. Results: A total of 192 patients with FSV were identified from the Congenital Heart Disease Center database during the study period. A total of 217 transcatheter interventional procedures have been performed in 109 patients (57%), 36 (17%) procedures were performed before Glenn operation, 65 (30%) between Glenn operation and Fontan completion and 116 (53%) procedures were performed after Fontan completion. Among patients who need transcatheter treatment, an average of 2 (1-8) procedures had been performed. Most frequent procedure was embolization of collateral vessels (54%), followed by percutaneous balloon angioplasty (27%), stent implantation (8%), balloon atrial septostomy or septoplasty (4%), fenestration occlusion (3%), and fenestration formation (2%). Twenty-two (10%) procedures had been performed during immediate post-operative period. There were 2 major complications. One was trancatheter formation of fenestration in Fontan baffle which caused uncontrolled tearing of the baffle, necessitating urgent surgical repair and fenestration. The other was retroperitoneal hemorrhage which was rescued by stent graft. There was another procedural failure during a transcatheter formation of fenestration in a patient who underwent extracardiac conduit Fontan operation using Gore-Tex짰 tube as an extracardiac conduit. Conclusion: Over half of patients with FSV may benefit from transcatheter intervention. Transcatheter therapy even after Fontan completion is useful and safe modality which may reduce the risk of re-operation. It is crucial for both the pediatric interventionist and the congenital cardiac surgeon to understand each other���s capabilities as well as to cooperate for the best outcome.