During embryonic development, anomalies usually occur at the primordial aortic arch (AA) level. One of these is the right retroesophageal subclavian artery (RSA). The anatomical and morphological variations of AA and its branches are significant for diagnostic and surgical procedures in the thorax and neck. The objective of the study was to report an RSA found during the dissection, correlating this with the corresponding clinical implications. A human female cadaver of unknown age and cause of death was used and conserved in 10 % formaldehyde and distilled wash. The dissection of the heart and large vessels was performed. There was particular emphasis one the AA, and development according to conventional techniques, removing the organ after dissecting the pericardium and dissecting the ascending aorta and the AA. External function and its collateral branches were fully preserved, where the RSA was located. The RSA presented a diameter at its origin of 12.13 mm. The length between the RSA and the common right carotid artery (CRCA) was 43.84 mm. The diameter of the esophagus at the cephalic and caudal level of the RSA has values of 17.59 mm and 13.82 mm respectively. Furthermore, the diameters of the trachea at cephalic and caudal level to the RSA, respectively, were 22.12 mm and 13.30 mm. Knowledge of this anatomical variant is of great interest when interpreting and guiding the diagnosis of potential causes of a dysphagia associated with a retroesophageal subclavian artery, and is even more important during dissection studies.

KEY WORDS: Subclavian Artery; Aberrant subclavian artery; Anatomic Variation.