Intracranial air is usually asymptomatic but carries a potential risk of increased intracranial pressure or meningitis which require immediate therapy. Although pneumocephalus is quite common following trauma, especially with a fracture involving paranasal sinuses it is a rare manifestation of chronic otitis media. In this report, a case with a tension pneumocephalus at the cerebellopontine angle following a chronic mastoid infection is presented and the possible mechanism, diagnostic measures and the surgical management is discussed.