A 61-year-old man receiving anticoagulant therapy after the aortic valve replacement underwent emergency surgery for acute appendicitis. Although the patient was intubated with difficulty, no immediate complications were evident after extubation. On the evening of the first postoperative day he complained of a sore throat, difficulty in swallowing and dysphonia. The swelling of the tongue with right-side predominance and the swelling of the right neck were observed. The right-sided sublingual hematoma was confirmed by CT. The symptoms improved with steroid administration. The possibility of airway obstruction due to hematoma of the tongue should be considered in patients on anticoagulant therapy.