A case of progressive, spontaneous, nontraumatic hemorrhage into the tonsil, soft palate, hypopharynx, and larynx in a patient receiving oral anticoagulants is presented. There was no evidence of bleeding into other parts of the body. The presenting symptoms of sore-throat, dysphagia and hoarseness were mild at the time of admission. However, the bleeding later caused upper airway obstruction and aspiration, and the clinical picture during hospitalization became dramatic and life-threatening. Physicians should be aware of such possible complications in anticoagulant-treated patients, and if a hematoma is found in the pharynx or larynx the patient should be admitted for close observation and treatment. To the best of our knowledge this is the first reported case of spontaneous hemorrhage into the tonsil in a patient on oral anticoagulation.