A 46-year-old female with profound sensorineural hearing loss in her left ear from childhood developed tinnitus and fluctuating hearing loss on the right side 8 years ago. Four years later, paroxysmal episodes of rotatory vertigo occurred with gradually increased frequency, lasting from half an hour to 2 hours and accompanied with nausea and vomiting. Audiometric test revealed severe sensorineural hearing loss in both of her ears. The tympanograms showed type A on both sides. The threshold of auditory brainstem response was 97 dBnHL in her right ear while no waves could be educed on her left side. Weakened right-sided vestibular function was confirmed on caloric testing and vestibular-evoked myogenic potential. A normal cochlear morphology and clearness cerebellopontine angle were shown in the MR imaging scan. She was diagnosed with Delayed Endolymphatic Hydrops.