OBJECTIVE: The objective of this study was to analyze functional results after stapes surgery in patients with congenital nonprogressive conductive deafness resulting from an isolated fixation of the stapes according to age and surgical procedure. STUDY DESIGN: The authors conducted a retrospective case series from March 1993 to December 2003 in patients from two tertiary referral centers. METHODS: Twenty-eight patients were operated on by stapedotomy or partial stapedectomy using Teflon stapes prostheses. The median age at surgery was 14.2 years (range, 8.3-29.1 years). Main outcome measures were clinical and audiometric evaluation before and after surgery. Mean air conduction (MAC) and bone conduction (MBC) thresholds were recorded at 0.5, 1, 2, and 4 kHz. The evaluation of functional outcome was based on the MAC gain, the MBC comparison, and the mean postoperative and residual air-bone gaps. RESULTS: The median preoperative MAC was 50 dB (range, 19.0-65.0 dB) with a 35.0 dB median dB air-bone gap. With a mean follow up of 19 months, postoperative hearing improvement was statistically significant: median gain of 32.5 dB (P<.001) and median residual air-bone gap of 3.5 dB. The MBC was also statistically improved with median pre- and postoperative MBC of 11.5 and 6.5 dB, respectively (P<.001). Results were not dependent on the age group or type of surgery (stapedotomy or partial stapedectomy). No perceptive hearing loss was observed despite one gusher case. CONCLUSION: Surgical treatment of isolated congenital stapes ankylosis allows good functional results regardless of age or type of surgery.