Interventional therapy of congenital heart lesions at cardiac catheterization has greatly increased during the past decade. At the authors' institution, the frequency of such procedures among catheterizations has increased from 5% to more than 60%. The variety of lesions so treated continues to expand and equipment continues to improve. These procedures may be divided into 2 groups, namely (1) those involving balloon dilation of stenotic valves and vessel obstructions with stent placement being increasingly used in the latter and (2) those involving occlusion of lesions with (a) coils, such as aortopulmonary collaterals, patent ductus arteriosi and coronary artery fistulae and (b) umbrella devices, such as atrial and ventricular septal defects. These have replaced surgery as the initial procedure of choice in many lesions including valvar pulmonary and aortic stenoses, and postoperative aortic coarctation in young patients. In addition, use of the double-umbrella device even in noncongenital lesions appears promising.