A technique to quantify the tandem Romberg test (posturography) was used to study ten patients with otosclerosis before (series 1), 48 hours after (series 2), and between two to four months after (series 3) a stapedectomy. The results were analyzed by power spectrum analysis and then compared to findings from electronystagmographic testing performed with series 1 and 3. There was no significant change in the electronystagmography (ENG) test findings between series 1 and 3. Posturography, however, demonstrated an uncompensated vestibular pattern in the immediate postoperative period which, after two months, converted to a compensated vestibular pattern. Posturography serves as a useful quantitative test for the study of patients with balance disorders because the procedure supplements rather than complements the ENG. In addition, posturography detects vestibular reflex abnormalities in stapedectomized patients two months afterwards. Other testing modalities have not consistently demonstrated this postoperative vestibular system instability.