A 32-year-old male with acute, left-sided petrositis rapidly developed ipsilateral pontine angle symptoms, i.e. paralyses of the fifth to eighth cranial nerves, lateral gaze nystagmus and disturbances of horizontal optokinetic nystagmus and horizontal smooth pursuit eye movement. Because the cranial nerve disturbance was more marked in the seventh and eighth cranial nerves than in the fifth and sixth nerves this case was considered to be a rare paralabyrinthitis type as opposed to the more common apicitis type. It was inferred that inflammation extended into the internal acoustic meatus causing the development of the disturbance of the seventh and eighth nerves. Also, localized pachymeningitis at this region and compression of the brain stem due to an extradural abscess was considered to be responsible for the development of the abnormal eye movement including lateral gaze nystagmus. The causative organism was proteus inconstans B and the patient recovered in about one month's time with adequate antibiotic treatment (Bactramin).