Isolated congenital stapes ankylosis is described in 32 operated ears from 28 patients. In 27 ears, a regular stapedectomy was performed. In the remaining 5 ears, 2 had stapes gushers, 2 had bony stapedial tendons, and 1 had an aberrant facial nerve crossing the oval window. The average individual hearing gain was 20 dB. The mean hearing gain for the 24 successful stapedectomies was 29 dB. In 24 of 32 ears (75%), an essential hearing gain of at least 15 dB Fletcher's index hearing threshold could be achieved. A Fletcher's index not exceeding 30 dB could be achieved in 19 of 32 ears (60%), in spite of several cases with a sensorineural component in the hearing loss. A review of the literature and overview of longer series with isolated congenital stapes ankylosis is presented.