A 62-year-old man was admitted to our department because of the sudden onset of dysaesthesia in the right perioral region of the face and right hand. Neurological examination demonstrated a loss of pain and temperature sensation in both the right perioral region and in the fingers of the right hand. These findings suggested damage to parts of the ipsilateral spinothalamic and trigeminothalamic ascending tracts, producing restricted sensory impairment of the perioral region and ipsilateral hand. This is the first reported case of a medullary lesion causing cheiro-oral syndrome.