Perivalvar leak following atrioventricular valve replacement can result in heart failure or hemolytic anemia. These patients may be poor surgical candidates given a complex clinical condition. We describe transcatheter closure of a perivalvar leak in a 3-month infant who had undergone left atrioventricular valve replacement with a St. Jude's prosthesis. Catheter Cardiovasc Interv 2004;61:548–551. © 2004 Wiley-Liss, Inc.