In a review of 126 heart specimens of simple complete transposition of the great arteries with ventricular septal defect (VSD), coarctation was noted in eight (6%). In 105 Taussig-Bing heart specimens, coarctation and/or aortic outflow tract obstruction was noted in 56 (53%) (p less than 10(-10). This was similar to our surgical experience in 26 patients with transposition and VSD or Taussig-Bing heart. Six of nine patients with Taussig-Bing heart also had coarctation of the aorta, whereas all 17 patients with transposition and VSD had a normal aorta. Four patients with Taussig-Bing heart underwent coarctation repair and pulmonary artery banding at 2 to 7 days of age. The remaining two patients with Taussig-Bing heart did not have a hemodynamically significant coarctation. Five of the six patients with Taussig-Bing heart and coarctation underwent a Senning procedure between the ages of 7 weeks and 3 1/2 years. In four (all less than 4 months of age) the VSD could not be closed through the tricuspid valve. A right ventriculotomy was done in two and contributed to their deaths. In the other two patients the VSD was left alone and the pulmonary artery banded. Both remain well. The fifth child, aged 3 1/2 years, had the VSD closed through the tricuspid valve but died in the postoperative period of renal failure. The sixth patient is awaiting further operation following coarctation repair and pulmonary artery banding. We conclude that the presence of coarctation strongly suggests that Taussig-Bing heart malformation exists rather than transposition and VSD. Pulmonary artery banding and coarctation repair are the initial procedures of choice in the management of these critically ill newborn infants. Increasing cyanosis and failure to thrive will necessitate further operation. Closure of the VSD through the tricuspid valve in these infants is difficult. Pulmonary artery banding in association with a Senning procedure is preferable to a right ventriculotomy. Closure of the VSD is then planned at a later stage.