The authors report a case of a 65-year-old male patient who, after complaint about retrosternal discomfort and going through a thoracic radiography with mediastinal enlargement, was submitted to magnetic resonance angiography, which detected a right aortic arch with aberrant left subclavian artery and Kommerell diverticulum. A literature review was the basis for our clinical conduct, for the surgical treatment is complex. The patient presented improvement with clinical treatment and, currently, is under ambulatory follow-up care, with control proposed for three months later or in case of worsening.