This report describes a rare case of acute life-threatening stridor due to membranous tracheitis that occurred as a complication of endotracheal intubation, performed for video-assisted thoracotomy. An obstructive fibrin clot was found in the subglottic region by bronchofiberscopy, and removal provided complete relief of the airway obstruction. The mechanism of the development of this fibrin membrane may have interacted with local tracheal trauma from the endotracheal tube. Membranous tracheitis should be considered in the differential diagnosis of stridor and airway obstruction after endotracheal intubation because it is a life-threatening complication of this procedure.