Cerebrospinal fluid (CSF) leak has been a constant and unresolved complication of acoustic tumor surgery. This study retrospectively reviews 381 primary acoustic tumor surgeries performed by a single, senior, neurotologist and neurosurgeon team from 1979 through 1991. There were 68 cerebrospinal fluid leaks in 66 patients (66/381; 17%). There was no significant difference in the incidence of CSF leak between the translabyrinthine group (21%) and the retrosigmoid transmeatal group (16%). Translabyrinthine leaks were evenly divided between rhinorrhea and the postauricular wound while retrosigmoid transmeatal leaks were predominantly rhinorrhea. Eleven of 14 translabyrinthine wound leaks responded to pressure dressing and suture. The remaining 3 ceased with continuous lumbar cerebrospinal fluid drainage. Ten of 14 cases of translabyrinthine rhinorrhea responded to continuous lumbar cerebrospinal fluid drainage, and those in whom it failed were cured with revision of the mastoidectomy/labyrinthectomy cavity. Twenty-one of 28 cases of retrosigmoid transmeatal rhinorrhea responded to continuous lumbar cerebrospinal fluid drainage, and those in whom it failed were cured with extracranial, transmastoid revision. The incidence of cerebrospinal fluid leak was not influenced by age, sex, size of tumor, postoperative hydrocephalus, or the intraoperative use of autologous fibrin glue. Meningitis was an unusual complication, occurring in 3% of all patients.