Abstract Two cases are described in which the aorta arises from the right ventricle while the pulmonary trunk arises above a ventricular septal defect from both ventricles, mainly the left. Anatomically, the condition herein called right ventricular aorta and biventricular pulmonary trunk lies between classic complete transposition of the great vessels, on one hand, and the Taussig-Bing complex, on the other. Distinguishing points are that in the Taussig-Bing malformation the pulmonary trunk which arises near a ventricular septal defect takes its origin entirely from the right ventricle. In the cases here described the biventricular pulmonary trunk straddles a ventricular septal defect and arises mainly from the left ventricle. Continuity between elements of the mitral and pulmonary valves, which is a characteristic of the cases here described, is not exhibited by the Taussig-Bing malformation. Origin of the pulmonary trunk from both ventricles is a major difference from the origin of that vessel in complete transposition. In the latter malformation the pulmonary trunk arises entirely from the left ventricle. The fundamental functional derangements, as judged by clinical examination and angiography, are more like those of the Taussig-Bing complex than those of complete transposition. From a surgical point of view, problems in correction seem to be more closely allied to those of complete transposition than to those of the Taussig-Bing complex.