1. Extracorporeal circulation with the pump oxygenator has been used for the repair of 31 atrioseptal defects with one mortality. Of these, 16 presented complicated lesions which probably could not have been corrected using a hypothermic technique. In all lesions a complete repair was meticulously effected without difficulty. To eliminate unnecessary periods of cardiopulmonary bypass, the lesions were assessed by a preliminary blind digital exploration. 2. In several cases, although the major defect was palpated by the blind exploration, multiple smaller lesions were not recognized until inspected visually. This, we believe to be responsible for the persistent postoperative arterialization of the right atrium reported by those using closed and semi-closed techniques. 3. In all cases the repair was effected in the beating heart, without arrest. 4. It is believed that congenital pulmonary valvular stenosis, too, is best repaired under direct vision, using extracorporeal circulation. The stenotic valve is supported by either two or three commissures. When the repair is effected under vision, the fused commissures can be incised accurately and meticulously, with the creation of a functioning tricuspid valve. In addition, the right ventricular outflow tract can be explored. 5. Eight uncomplicated pulmonary valvular stenoses have been corrected without mortality. A ninth, associated with an interventricular septal defect, and a tenth, associated with transposed right upper lobe veins, were also corrected without mortality.