The secundum atrial septal defect (ASD) is noted to occur in 1 per 1,500 live births and is the fourth most common congenital heart defect (CHD) [Anzai et al. in Am J Cardiol 93:426–431, 2004]. Early complications with percutaneous closure of secundum ASDs include device malposition and embolization, arrhythmias (primarily atrial fibrillation), pericardial effusion, residual shunt, and thrombus development on the left atrial disk [Chessa et al. in J Am Coll Cardiol 39:1061–1065, 2002, Co-Burn and William in Moss and Adams’ Heart disease in infants, children and adolescents including fetus and young adults. Williams and Wilkins, Baltimore, 1995]. We present a patient with a very late complication of device thrombus after percutaneous secundum ASD device closure.