Diabetic patients with autonomic dysfunction are potentially poor risks for anesthesia and particular care is needed during and after surgery. We here report a 48-year-old male patient with diabetes mellitus who suffered from intraoperative hypotension and bradycardia which did not respond to ephedrine and atropine treatment and eventuated in cardiac arrest. A heart rate variability study confirmed the diagnosis of autonomic dysfunction after the event. Possible predisposing mechanisms and anesthetic considerations are discussed.