Anomalous origin of the right subclavian artery (ARSA) from the aorta distal to the normally positioned left subclavian artery is a relatively frequent congenital anomaly in subjects with left aortic arch. The purpose of this study was to determine the relative frequency of associated cardiovascular anomalies in individuals with this anomaly. From the records of approximately 11,000 pathologic specimens in the Registry of Cardiovascular Disease of United Hospital (St. Paul, MN, USA), we found 128 (1.2%) with ARSA. Of the 128 ARSA, 117 (2.9%) occurred among 4102 instances of congenital heart disease. The 117 cases with congenital heart disease and ARSA were conotruncal anomalies in 38%, septal defects in 28%, obstructive anomalies of the left side of the heart in 21%, right heart anomalies in 5%, and miscellaneous conditions in the other 8%. Down syndrome existed in 14 (12%) of the 117 specimens with ARSA and some congenital cardiac anomaly; nine of the latter had an atrioventricular canal (AVC) malformation.