The author recently experienced a case of cholesteatomatous otitis media with intracranial complication and acute brain syndrome. Patient was a 25 year old male who had chronic suppurative otitis media over 15 years. On admission, he had symptoms of purulent otorrhea, severe headache, vomiting and had acute brain syndrome of disorientation, impairment of judgement & memory, confusion, mild delirium with clouding of consciousness. Under the diagnosis of otogenic intracranial complication associated with acute brain syndrome, radical mastoidectomy was performed. Shortly after and operation, aural symptoms and mental symptoms were improved progressively.