A piriform sinus fistula is not usually present during the newborn period. We report a case of piriform sinus fistula causing a life-threatening respiratory obstruction in the period immediately after birth. Radiographs and computed tomography (CT) showed an air-containing retropharyngeal cyst. Cystostomy was carried out because the upper respiratory obstruction had worsened. We diagnosed a piriform sinus fistula using a laryngeal fiberscope and coloring matter. Moreover, threedimensional CT was contributory to the diagnosis. Finally, total resection of the cyst was conducted and the patient left our hospital without any obvious complications.
