Patients with far-advanced otosclerosis (FAO) may appear to be suffering from profound sensorineural hearing loss and are frequently directed to cochlear implantation programmes. In order to avoid such misdiagnosis, FAO should be considered in patients with non-measurable bone-conduction levels and air-conduction levels exceeding 85 dB. Specific clues can lead the clinician to suspect otosclerosis as the aetiology of hearing loss. A review of eight patients (nine ears) with FAO who underwent stapedectomy from 1985-1995 reveals that six of the eight (75 per cent) who had been unable to use a hearing aid preoperatively obtained serviceable hearing with a hearing aid after surgery. This confirms that cochlear implantation is not the best treatment for all profoundly deaf patients; some are better off with stapedectomy.