A thirty nine year-old male patient was scheduled for emergent craniotomy and epidural hematoma evacuation under general anesthesia. All data of the preoperative check lists for emergent operation were within normal limits and vital signs of the patient were stable. During the induction of anesthesia an armored tube was inserted into the trachea for this operation. Approximately 110 minutes after the induction of anesthesia, signs of complete airway obstruction developed abruptly. At that time we deflated the cuff balloon to exchange the tube. Then, the signs of airway obstruction disappeared completely. Therefore the deflation of cuff balloon is recommended in order to exclude the obstruction by the displaced cuff.