A study was carried out to evaluate the results of stapes surgery in 53 cases of otosclerosis. The hearing function was measured pre- and postoperatively by means of conventional and high-frequency audiometry (Demlar 20K). The operative findings of the gradation of otosclerosis were compared with the pre- and postoperative audiometrical measurements. The results of this study point out that a clear relation exists between the preoperative high-tone audiogram and the gradation of otosclerosis. Stapedotomy does not influence the high-frequency threshold postoperatively. In conclusion, high-frequency audiometry can predict the state of stapes fixation in otosclerosis and this can be important in stapes surgery.