AbstractA case of double superior venae cavae with bilaterally symmetrical azygos veins is recorded for a 45 year old Caucasian male cadaver with no history of cardiovascular disorder. Death was reported as resulting from carcinoma of abominal viscera with extensive metastases.A review of the literature since 1887 indicates that this is an addition to 216 cases of double superior venae cavae and seven cases of double azygos veins previously reported in cadavers.A typical left brachiocephalic vein was absent. The anomalous vena cava, formed by union of left internal jugular and left subclavian veins behind the sternoclavicular joint, coursed vertically through the superior mediastinum, continued through the atrioventricular sulcus and opened into the right atrium near the orifice of the inferior vena cava. It was almost completely symmetrical with the right and received a complete azygos vein.The anomaly is explained as (a) failure of the precardinal anastomosis to form, (2) persistence of the entire left anterior and common cardinal veins and left horn of the sinus venosus, and (3) persistence of the proximal part of the left posterior cardinal which with the left supracardinal forms the left azygos vein. Morphological and clinical significances of the anomaly are discussed.