The left aortic arch with an aberrant right subclavian artery, or arteria lusoria, is the most common aortic arch anomaly, occuring in 0.5-2.5% of individuals. Four vessels arise sequentially from the aortic arch: the right common carotid artery, the left common carotid artery, the left subclavian artery and the aberrant right subclavian artery, which crosses upwards and to the right in the posterior mediastinum. It results from a disruption in the complex remodelling of the paired branchial arches, typically of the right dorsal aorta distal to the sixth cervical intersegmental artery. The diagnosis and differentiation of arch anomalies is based on findings at chest radiography in association with those at esophagography. It is usually asymptomatic. When symptomatic, it produces dysphagia lusoria or dyspnea and chronic coughing. Treatment is indicated for symptomatic relief of dysphagia lusoria and for prevention of complications due to aneurysmal dilatation.