Many of the transcatheter devices described in this article remain investigational in the United States. Currently, we consider the applications of these techniques as either (1) procedures of choice (for closures of patent ductus arteriosus, balloon dilation or stent implantation for peripheral pulmonary stenoses, balloon dilation of recurrent or persistent aortic coarctation, balloon pulmonary valvotomy, closure of congenital muscular or postoperative residual ventricular septal defects, closure of patent foramen ovale in the setting of cyanosis, balloon aortic valvotomy, fenestration closures, coil embolization of thoracic collateral vessels); (2) effective alternatives to surgical therapy (closures of atrial septal defects of the secundum type, balloon dilation of native aortic coarctation, stent implantation for conduit or baffle obstruction, device emobolization of paravalvular leaks or coronary artery fistulas); or (3) treatments with unproven effect (closure of acute postmyocardial infarction ventricular septal defects, closure of patent foramen ovale for idiopathic stroke, stent implantation for pulmonary venous stenosis) (Table 1). Patients with congenital heart disease often undergo multiple catheterizations and surgical therapies, each with its own complications and sequelae. Clinical trials of catheter-based technologies for patients with congenital heart disease have consisted of uncontrolled case series with a lack of standardized follow-up. Additional prospective large-scale clinical trials of these therapies seem necessary before their widespread acceptance.