Objectives/hypothesis: Objective tinnitus is a symptom often observed in patients with chronic hyperactivity of masticatory muscles. Methods: We report here the unusual case of a 63-year-old woman who developed a distressing tinnitus related to contractions of reinnervated masticatory muscles. This reinnervation process was caused by a postpolio syndrome that gave rise to an acoustic resonance phenomenon transmitted to the middle ear as an audible sound. Results: The tinnitus was successfully treated with electromyography-guided intramuscular injections of type A botulinum toxin. Conclusion: The intramuscular injection of botulinum toxin was found to be effective in relieving severe and disabling postpolio tinnitus.