Among 400 patients with rheumatoid arthritis and measurable ramus height there were 76 patients with mutilating arthritis of the temporomandibular joints. In 30 of these 400 patients, episodes of upper airway obstruction had occurred, mostly when the patient lay supine. Laryngoscopy had been performed in only 7 patients, and in 3 of those a laryngeal arthritis was detected. Upper airway obstruction had occurred significantly more often in patients with arthritis of the temporomandibular joints than in those with normal joints. In 70% of the patients with a severe arthritic destruction of the temporomandibular joints, episodes of airway obstruction had occurred. Upper airway obstruction is assumed to occur in those patients due to a pharyngeal obstruction, as in other patients with micrognathia or sleep apnea syndrome.