This study aims to determine the benefit of stapes surgery for otosclerosis in 121 patients with a mixed hearing loss and a preoperative bone conduction (BC) threshold >30 dB. Average postoperative air conduction (AC) improved from 61.5 dB to 34.3 dB. Average air-bone gap closed from 27.1 dB to 6.1 dB. Bone conduction improved from 34.3 dB to 28.2 dB, with 38% of patients achieving a postoperative AC of <30 dB. Glasgow Benefit Inventory scores showed significantly increased quality of life postoperatively in the 88 patients who responded to follow-up, with an average score of 56. There was a mean reduction in daily hearing aid use postsurgery of 5.48 hours, with 56% of patients who responded to follow-up questionnaire no longer needing to use one. When assessing suitability for stapes surgery, surgeons should consider that preoperative BC thresholds may be a poor indicator of the true cochlear reserve and therefore the potential for improvement in AC thresholds and quality of life.