A 55-year-old woman noticed progressive hearing loss, earache and tinnitus in the left side in December 1988, followed by dysesthesia of the left face and hypogeusia. Those symptoms did not respond to the otological treatment of otitis media. In addition, the left eyelid ptosis, double vision and dysphagia appeared in May 1989. On admission, cranial nerves from III to XII were affected exclusively in the left side. The cell counts and the protein levels in the CSF were elevated. The MRI of the head showed hypertrophic dura mater at the left base of the skull covering the temporal lobe. No bone destruction was found in CT. The biopsy revealed the thickened dura mater with microabscess containing Langhans giant cells and lymphocytes. A diagnosis of pachymeningitis was made. After the therapy with antibiotics and then with prednisolone for several months, cranial nerve disturbances disappeared except hearing loss with decrease in cell counts and protein levels of the CSF. The follow-up MRI after one year showed decrease in thickness of dura mater. The MRI, particularly using enhancement with Gd-DTPA, was useful to make a diagnosis of hypertrophic pachymeningitis. It is suggested that the administration of antibiotics should be considered in the treatment of the pachymeningitis even if the causative agents were not identified.