Objective: To observe the long-term outcome of ossiculoplasty using autogenous mastoid cortical bone in chronic otitis media in-patients. Methods: Sixty-one ears of 57 in-patients with chronic otitis media, with or without cholesteatoma, underwent type III tympanoplasty using autogenous mastoid cortical bone as the prosthetic material. Twenty-one ears were treated by canal wall down mastoidectomy and 40 ears by canal wall up mastoidectomy. The follow-up period was 3 to 6 years (average 4.2 years). Pure tone averages for thresholds at 0.5, 1, 2 and 3 kHz were calculated using standard conventional audiometry. Results: The pre-operative mean air-bone gap of 31.6 dB, for all ears, was reduced to 20.3 dB post-operatively. For the 40 canal wall up ears, this value decreased from 30.8 dB to 19.9 dB, and for the 21 canal wall down ears it decreased from 33.0 dB to 21.0 dB. The differences between the pre- and post-operative mean air-bone gap values were significant. Conclusion: No cases of extrusion, necrosis or resorption were exhibited for the autogenous mastoid cortical bone prosthesis. A significant hearing improvement was obtained in the majority of cases and this remained stable over time.