The patient was a 42 year old male with diabetes, which was induced apparently by ingestion of Vacar' (RH-787) 2 years ago. As diabetic complication, he has had episodes of intermittent symptomatic hypotension, diarrhea, impotence and anhidrosis. During his admission, his autonomic neuropathy was confirmed by several tests including thc abnormal responae of pulse rate to deep breathing. The insulin treatment was started and the patient experienced recurrent hypaglycemic attack srveral times. After one of hypoglycemic attack, patient developed the acute respiratory failure with respiratoy acidosis without any appreciabe reasons. The incident needed artificial ventilation for 12 days to disappear spontaneously. We emphasize the significance of acute respiratary failure as a spccific feature of autonomic neuropathy,