A 55 year old man with malignant rheumatoid arthritis (MRA) was admitted because of severe snoring during sleep and hypersomnolence in the day time. The patient developed an episode of respiratory distress and cardiac arrest, which responded rapidly to tracheal intubation and mechanical ventilation. He could be easily weaned from ventilator after 3 days. Polysomnography showed that the patient had an obstructive sleep apnea syndrome. Lateral view of cranial radiography revealed acquired micrognathia and destruction of the temporomandibular joints caused by RA, which induced obstructive sleep apnea. It is important to consider that obstructive sleep apnea can occur in RA patients showing snoring, hypersomnolence and disordered sleep behavior.