The purpose of this study was to evaluate and compare the results obtained in a group of implanted otosclerotic patients with a group of cochlear implant (CI) patients not affected by otosclerosis.Retrospective case review.Tertiary referral center.Nine patients affected by profound sensorineural hearing loss caused by otosclerosis and nine patients affected by profound sensorineural hearing loss not caused by otosclerosis were evaluated.Cochlear implantation.Preoperative imaging, intraoperative findings, postoperative facial nerve stimulation, and speech perception performance measures were performed and the data analyzed.Otosclerosis patients showed signs of cochlear ossification both on high-resolution computed tomography scans and intraoperatively. The incidence of facial nerve stimulation was higher in the otosclerosis group, three out of nine, and was generally related to the use of electrical stimulation from the Nucleus 22 cochlear implant. Psychophysical and speech perception measures did not show significant differences between the two groups, despite some otosclerosis patients showing increased electrical thresholds and comfort levels and slightly poorer speech perception performance scores.Patients with otosclerosis who have progressed to profound hearing loss derive significant benefit from cochlear implants; however, an increased risk of cochlear ossification and facial nerve stimulation has to be taken in account during preoperative counseling. The advance in imaging techniques, CI technology and the possibility to stimulate precise regions of the cochlea with lower intensities make it possible for the surgeons and audiologists to readily and successfully manage these complications as they arise.