A 52-year-old man with a history of prolonged heavy smoking who had undergone reconstructive oral surgery and neck dissection 2 months earlier developed a postoperative infection and was scheduled to undergo reconstructive oral surgery for the second time. His tongue and neck mobility was limited, and trismus and narrowing of the upper airway were observed. Nasotracheal intubation was performed under intravenous sedation using a bronchial fiberscope. Anesthesia was induced and was maintained uneventfully. Although the scheduled operation time was 4 hours, the procedure actually took more than 8 hours. His airway was reassessed at the end of surgery prior to extubation. The possible difficulty of a re-intubation was raised as a concern, but extubation appeared to be possible because there were no signs of airway swelling or increased respiratory secretions. Ventilatory impairment was not observed after extubation. However, an airway obstruction developed suddenly, beginning with a difficulty in clearing airway secretions 40 minutes after his return to the ward. Because of the limited retroflexion of the cervical region, the unfavorable conditions on the hospital ward, and the anatomical changes after the first surgery, the oral surgeon require a long period of time to perform an emergency tracheotomy. Although the patient developed temporary cardiopulmonary arrest caused by hypoxia, he recovered consciousness following the removal of the upper airway obstruction after the tracheotomy. He was discharged with no brain damage and no severe disability. In the present case, the cause of the acute airway obstruction may have been the difficulty in clearing the copious and viscous secretions derived from smoking in addition to upper airway narrowing caused by the previous and present surgery. In difficult re-intubation cases where an airway obstruction seems likely, an elective surgical tracheotomy should be considered.