Congenitally corrected transposition of the great vessels is an important basic anomaly of the heart which has only recently received wide clinical attention. First described by von Rokitansky in 1875 (33), the anomaly remained a clinical curiosity until modern surgical advances in the treatment of congenital heart disease made accurate diagnosis important. Less than 150 cases are described in the literature, but the condition cannot be extremely rare, since we have encountered more than 30 cases, and similar large series have been reported from other institutions (17, 27). Among our cases is the first example of congenitally corrected transposition without associated anomalies diagnosed on the basis of chest films, the second such case to be recognized in life. Basic Anatomy of Corrected Transposition of the Great Vessels The aorta and pulmonary artery are transposed so that the aorta arises on the left and ventrad, in the usual position of the pulmonary artery, while that vessel arises on the right and ...