Anomalies of pulmonary venous return are being recognized with increasing frequency and in the past fifteen years have been the subject of well over a score of papers. These have, for the most part, been anatomic studies, but in the last few years a number of reports have been devoted to the clinical aspects of this cardiovascular anomaly. Pulmonary veins have been found to drain anomalously into the superior vena cava, the coronary sinus, the portal vein, the right atrium, the innominate veins, the sinus venosus, the azygos vein, and even the thoracic duct (14). All or part of the pulmonary venous blood may be diverted from the left atrium into systemic veins. One of the more frequent aberrations of pulmonary venous return is the emptying of the pulmonary veins into a left vertical vein (14). The latter is a wide vertical vascular structure to the left of and adjacent to the base of the heart, linking the pulmonary veins with the left innominate vein. The course of the circulation is shown in Figure 1. There is much divergence of opinion concerning the development of this anomalous vessel and its communications. Some authorities attribute it to retention of one or the other of the original communications between the presplanchnic plexus and pulmonary anlage (3, 5, 6, 15). Another opinion is that it is due to failure of the pulmonary veins to communicate primarily with the heart, leading to free communication between the pulmonic and systemic veins (7). Others feel that from the present state of knowledge there is no rationale for the anomaly (10, 12). Previous authors have referred to the left vertical vein as a persistent left superior vena cava. This designation is probably incorrect, since the structure has no communication with the coronary sinus and lies anterior to the position of a true left superior vena cava. Cases of true left superior vena cava, with and without a companion right superior vena cava, have been described (19, 20, 25). These represent persistence of the left precardinal vein communicating directly with the coronary sinus. Normally, the left precardinal vein loses its communication with the left common cardinal vein (which persists as the coronary sinus) and remains only as the left superior intercostal vein (1, 22). Snellen and Albers (23) were the first to refer to the structure in question as a left vertical vein. The purpose of this report, based on 4 cases of anomalous drainage of the pulmonary veins into the left vertical vein, is to call attention to the highly characteristic roentgenologic features of this cardiovascular anomaly. It is of practical importance that such cases be recognized, since there is reason to believe that some of them may be amenable to surgical correction. To the authors' knowledge, there has been no report on this entity in English roentgenologic literature. Case Reports Case I: A boy of 3 1/2 years was admitted to the hospital on June 18, 1951, because of congestive heart failure.