This article reviews the authors' experience with autoimmune endolymphatic hydrops over the past 5 years. Twenty-seven of 52 patients with diagnosed autoimmune inner ear disease (52%) manifested endolymphatic hydrops, usually bilateral. Treatment consisted of low salt diet, diuretic, vestibular suppressant, and usually prednisone. Cytotoxic drugs and lymphocytoplasmapheresis were reserved for refractory cases. Audiometric followup (average, 23 months) was available in 12 patients. Using American Academy of Otolaryngology--Head and Neck Surgery guidelines, hearing improved or stabilized in at least one ear in nine patients and deteriorated bilaterally in three patients. Vestibular treatment results paralleled auditory treatment results. Autoimmune endolymphatic hydrops should be considered in the differential diagnosis when symptoms are bilateral and do not respond to conventional therapy or when immune laboratory tests are positive. In suspect patients, medical therapy with prednisone, and rarely cytotoxic drugs and lymphocytoplasmapheresis, should be recommended. Further research is needed to determine whether surgery should be performed in medically unresponsive cases.