ObjectiveTo evaluate the indications for, techniques used in, and patient outcomes after surgery with the transcochlear approach in the treatment of petroclival tumors.MethodsRetrospective review of 24 cases between 1985 and 1995 at the House Ear Clinic (Los Angeles, CA, U.S.A.).ResultsMeningioma was the most common tumor. Complete removal was achieved in 82% of tumors after one-or two-stage surgeries (average follow-up time, 36 months). The second-stage surgery was a middle fossa transpetrous approach. Most patients had some degree of facial nerve dysfunction immediately after surgery, and 12 of 20 patients subsequently improved to House-Brackmann Grade III or better. Fifty-nine percent of patients had permanent neurologic sequelae because of either the surgery or their disease.ConclusionThe transcochlear approach is best suited to treating petroclival intradural tumors that extend ventrally to the brainstem in patients without serviceable hearing. Temporary facial weakness is expected as a result of posterior facial nerve transposition.