PROBLEMS/OBJECTIVES: Tumour size, intra-operative electrophysiologic thresholds and postoperative facial nerve function have been demonstrated to be important predictors of ultimate facial nerve function after vestibular schwannoma surgery. In general little attention has been given to the prediction of outcome of facial nerve function in non-vestibular schwannoma tumour surgery of the cerebellopontine angle (CPA). METHODOLOGY: A prospective study was performed to assess the predictive value of patient, tumour histology and electrophysiologic factors in the estimation of ultimate facial nerve outcome after this form of surgery. RESULTS: Sixteen patients satisfied the requirements of the study. Poor long-term facial nerve outcome was associated with abnormal pre-operative facial nerve function, facial nerve schwannomas, premeatal meningiomas and electrophysiologic stimulation thresholds of greater than 0.1 mA. CONCLUSIONS : It is concluded that tumour histology and pre-operative facial nerve function are additional factors that must be considered in the prediction of facial nerve function after non-vestibular schwannoma surgery of the CPA.