A 19-month-old boy suffered from stridor and dysphagia. He was taking asthma medication for a few months, but symptoms did not improve. After admission, a chest CT showed a posterior mediastinal mass, which compressed the trachea and esophagus. The removed mass via open thoracotomy was a bronchogenic cyst on histopathology. Postoperatively, stridor and dysphagia disappeared. In case of persistent and refractory stridor or dysphagia in children, congenital lesions including bronchogenic cyst need to be ruled out.