A case of double aortic arch is reported. The male patient, 11-month-old, had breathed with a constant stridor since his birth and had frequent attacks of respiratory tract infection and dyspnea. The child was admitted because of restlessness, fever, stridor and cough. Dyspnea with cyanosis appeared later, and required intubation and mechanical ventilation. After then, three attempts to extubate the infant were made, but failed. A double aortic arch was suspected by bronchogram, esophagogram, and confirmed by cardiac catheterization. Through a left thoracotomy, the smaller left arch and the ligmentem arteriosum were divided to relieve the obstruction of trachea from the compression of the vascular ring. Postoperative convalescence was normal. Symptoms of double aortic arch vary with the degree of obstruction of the trachea and esophagus, ranging from mild to life-threatening respiratory obstruction and apnea. Inspiratory stridor, dyspnea, and wheezing, which are accentuated with feeding, crying, or respiratory infections, are characteristic clinical findings. The diagnosis is established by aid of an esophagography. Left thoracotomy, with division of the smaller aortic arch, is the only satisfactory treatment.