Diagnosis and treatment of petrous apex tumors are difficult. The paucity of their presenting symptoms stands out in sharp contrast with an often massive tumoral spread. Their diagnosis is sometimes of an uncertain nature in spite of M.R.I., requiring a biopsy by the middle fossa approach. Electron microscopy should always be requested. Surgical excresis is always delicate by one of the following approaches: middle fossa, translabyrinthine, infra-temporal, transcochlear. The clinical series presented here consists of 7 cases of cholesteatomas, 4 cases of chondrosarcomas and 1 case of giant-cell fibrous histiocytosis.