A 58-year-old man presented with a longstanding history of dysphagia and sensation of something lodged in the back of his throat. He had no significant past medical history, was a smoker (30 pack-years) and used >60 units of alcohol per week. A physical examination was unremarkable. The patient was referred to the respiratory clinic at Tygerberg Hospital, Cape Town, by a specialist physician who was concerned about the patient's abnormal chest radiograph (Fig. 1).The chest radiograph showed that the normal left-sided aortic arch and the usual companion descending aorta were absent. The arch coursed to the right with the descending aorta also on the right. A computed tomography (CT) scan (Figs 2 and 3) and reconstructions (Figs 4 and 5) confirmed the right-sided aortic arch with a retrooesophageal aberrant left subclavian artery and formation of a Kommerell's diverticulum at the origin. In the absence of major complications, he was managed conservatively. DiscussionThe prevalence of a right-sided aortic arch among adults is ~1/1 000 -2 000 of the population.[1] With this rare congenital anomaly, the aortic arch and the descending thoracic aorta are situated in the right hemithorax. During the third week of gestation, the aortic arch develops. The arch is formed by the left fourth aortic arch vessel while the right fourth vessel regresses.[1] The two dorsal aortas fuse (or the right dorsal aorta involutes) to form the descending aorta, and the ventral aortic limbs fuse to form the aortic sac. In individuals with a right-sided aortic arch, the right dorsal aorta and right fourth CASE REPORT