Immune-mediated inner ear disease, first described by McCabe in 1979, typically presents with an idiopathic, rapidly progressive bilateral sensorineural hearing loss. The course of the hearing loss occurs over weeks to months. It may occur in both sexes and at a variety of ages, but is most common in middle-aged females. It may be accompanied by tinnitus, Meniere's-like vertigo, or more commonly, ataxia or unsteadiness. Approximately 30% of patients will have associated systemic immune-mediated disease. Although refinements in laboratory tests for specific inner ear antigens are being made, and non-specific laboratory indicators of inflammatory or systemic immune disease may be useful in confirming the diagnosis, the most important diagnostic finding is the improvement in hearing seen with a trial of immunosuppressants. This report includes a typical evaluation of the patient with suspected immune-mediated inner ear disease and an illustrative case. Sensorineural hearing loss due to immune-mediated inner ear disease, although unusual as a cause of hearing loss, is important to recognize because early diagnosis and treatment can have a marked effect on the clinical outcome.