In a full-term infant who underwent surgery for type III esophageal atresia, attempts to remove the tracheal tube postoperatively failed. Bronchoscopy disclosed external compression of the trachea in the chest. Selection of the investigations most likely to provide the etiologic diagnosis was discussed. Because of the patient's poor general condition, MRI of the mediastinal area was performed first and showed an abnormal origin of the brachiocephalic trunk which was the cause of tracheal compression. No attempt at corrective surgery was made and the patient was successfully extubated at four months of age.