We report the 25-year follow-up on the first reported case of odontoma in the middle ear. Diagnosis of odontoma had been made on the basis of radiography films that showed a middle ear mass with multiple toothlike areas of radiopacity. No clinical intervention was recommended. At 25-year follow-up, audiometry showed progressive mixed hearing loss on the affected side and mild ipsilateral sensorineural hearing loss. Computed tomography better characterized the discrete mass, which was shaped similar to a dental crown. To avoid jeopardizing cochlear and facial nerve function, no surgical intervention was pursued, and we recommended use of a BiCROS (bilateral contralateral routing of signal) hearing aid.