Cogan's syndrome (CS) is a chronic inflammatory disorder of unknown etiology that most commonly affects young adults. Clinical hallmarks are bilateral interstitial keratitis and vestibuloauditory dysfunction. Association between CS and systemic vasculitis as well as aortitis also exists. The diagnosis of CS is based upon presence of characteristic inflammatory eye disease and vestibuloauditory dysfunction. We describe classic Cogan's syndrome in a 47-year-old female from Ardabil. The patient was admitted with headache, vertigo, nausea, vomiting, right leg claudication, musculoskeletal pains, bilateral hearing loss, and blindness for the past two months. Ophthalmologic examination revealed that visual acuity was 0.1 bilaterally. Conjunctival hyperemia, bilateral cataract, and interstitial keratitis were detected with a slit lamp examination. Pure tone audiogram (PTA) and auditory brain stem response (ABR) showed bilateral sensorineural hearing loss. The other differential diagnosis of CS was studied and ruled out. Pulse i.v. methylprednisolone and cyclophosphamide were given and were followed by oral prednisolone and cyclophosphamide. Clinical follow-up showed partial improvement.