A new entity, the giant apical air cell syndrome, is presented and its surgical management is described. The syndrome triad consists of a giant apical air cell, spontaneous CSF rhinorrhea, and recurrent meningitis. Constant pounding of the brain against the dura overlying the giant air cell eventually, cause dural rupture and CSF leak. The giant apical air cell communicates with the eustachian tube creating a direct route for CSF to leak from the subarachnoid space into the nasopharynx. The syndrome is best diagnosed by polytomography of the petrous apex, surgical exploration, and careful dissection using the operating microscope. Dye or contrast studies are no longer necessary. Extracranial surgical management is preferable to the intracranial approach. Tympanomastoidectomy is performed with obliteration of the eustachian tube, middle ear, and mastoid. In this manner, the subarachnoid space is separated from the nasopharynx, preventing further episodes of meningitis. A detailed knowledge of the regional anatomy and the application of basic surgical principles should enable the temporal bone surgeon to accurately diagnose and manage most CSF fistulae.