A 70-year-old man presented with unilateral lateral medullary infarction, and then died of rapidly progressive respiratory failure within a day. The clinical manifestations were hiccups, hoarseness, dysarthria, nystagmus, left central facial paralysis, paralysis of the left soft palate, dysphagia, decreased superficial sensation over the right face and upper limb, and cerebellar ataxia in the left upper and lower limbs. The arterial blood gas analysis revealed mild hypoventilation. Soon thereafter, an apneic episode occurred during a sleep and advanced to ataxic respiration, and the patient died. Pathologically, there were fresh ischemic infarction localized to the left dorsolateral area of the upper medulla, caused by atherothrombotic occlusion of the left vertebral artery. These foci were in the areas including the medullary reticular formation, the solitary nucleus, the intramedullary fibers of the vagus nerve, and the nucleus ambiguus on the left side. We attributed the fatal acute progressive respiratory impairment in the present case to impairment of the automatic respiratory system (Ondine's curse) rather than the voluntary respiratory system.