A patient having the diagnosis of an anterior inferior cerebellar artery insufficiency died 36 hours after the onset of the symptoms that allowed this diagnosis. The special features of this study include a known symmetric 40-dB hearing loss 1 year prior to the onset of the symptoms, the noted decrease in hearing and severe vertigo heralding the vascular accident, the ensuring neurologic deficits, and the short duration of the patient's life after the onset of her symptoms. The patient's clinical course and the histopathologic findings of the brain stem involved the vestibular nuclei, facial nerve, nuclei of nerve V, restiform body and middle cerebellar peduncle and labyrinth including loss of sensory epithelium of the cochlea and vestibular system and the ganglion cells of Scarpa's ganglion. These findings are correlated with previous animal studies and those of Reye's syndrome. To the authors' knowledge this is the first report of a temporal bone histopathologic study from a patient having had the diagnosis of a labyrinthine arterial vascular accident.