Corrected transposition of the great vessels is characterized by transposition of the aorta in front and to the left of the pulmonary artery and inversion of the ventricles and atrioventricular valves. Unless it is associated with an intracardiac defect, the circulation of blood inside the heart is normal, and the anomaly may not be recognized clinically. The altered anatomy requires important modifications in the technical features of operative correction of associated cardiac defects. Among 53 patients with corrected transposition of the great vessels, 31 underwent operation for associated intracardiac defects. These were ventricular septal defects (11 patients), tetralogy of Fallot (seven), common ventricle (five), single ventricle (three), tetralogy of Fallot with pulmonary atresia (two), pulmonary stenosis (one), pulmonary atresia (one), and tetralogy of Fallot with common ventricle (one). Postoperative complete heart block, which usually leads to a fatal outcome, may follow closure of ventricular septal defect when conventional techniques are used. Although only one death from heart block occurred in seven patients operated on through a right ventriculotomy, we have employed left ventriculotomy in the last two patients to reduce the risk of heart block and to afford better exposure of the ventricular septal defect. The presence of preoperative complete heart block does not contraindicate correction of associated defects, but consideration should be given to insertion of a pacemaker at the time the lesion is corrected since these patients are likely to have Stokes-Adams attacks later. The anatomical features of associated common ventricle, single ventricle, and tetralogy of Fallot present such severe technical problems that complete correction of these anomalies is accompanied by a high risk. Total correction of tetralogy of Fallot was successfully carried out in only one of seven patients. Others were treated by some form of systemic-pulmonary shunt with good results. Two patients with tetralogy of Fallot and pulmonary atresia and one patient with pulmonary atresia were also treated by systemic-pulmonary shunts and obtained satisfactory palliation. One patient with pulmonary stenosis underwent successful transventricular pulmonary valvulotomy. A ventricular septum was created in five patients with common ventricle. There were only two survivors; the other three died of complete heart block. Recognition of corrected transposition of the great vessels associated with an intracardiac defect that requires operative repair is important because of technical problems that the morphological alterations of ventricular inversion impose.