To establish the risk of carotid artery stent (CAS) complications in patients with aortic arch anomalies. In a prospective series of patients submitted to CAS, all cases with arch anomalies were compared with cases with normal arch anatomy (type I, II and III) in order to assess the impact of anatomic characteristics on technical and clinical outcome. Outcome was evaluated in term of neurological complications and technical success. Of 214 consecutive patients undergoing CAS, 189 (88.3%) had normal arch anatomy and 25 (11.7%) arch anomalies. The arch abnormalities included common origin of brachiocephalic trunk and left common carotid artery in 22 cases (10.2%), separate origin of right subclavian and common carotid in 2 cases (0.9%) and left common carotid agenesis with separate arch origin of internal and external carotid in 1 case (0.5%). The two groups were not different in term of epidemiology and preoperative clinical and morphological characteristics. Technical failure occurred overall in 26 cases (12%) and neurological complication in 14 cases (6.5%). All symptoms were temporary. Technical failure was higher in the arch anomaly group; however the difference did not reach statistical significance (89.6% vs 76.4%, P=0.1). Neurological complications occurred more frequently in the arch anomaly group (20% vs 5.3%, P=0.039). Type of arch was the only variable independently associated with neurological complications (OR=2.01, p=0.026). Aortic arch anomalies are not infrequent and are associated with increased risk of neurological complications. The indication for CAS should be carefully evaluated in these cases.