 Menieres disease is a chronic illness that affects a substantial number of patients every year worldwide. The disease is characterized by intermittent episodes of vertigo lasting from minutes to hours, with fluctuating sensorineural hearing loss, tinnitus, and aural pressure. It has recently been suggested that viral etiologies specially Herpes virus might be the underlying reason. The investigators study is a randomized, double- blinded placebo-controlled clinical trial in Amiralam Hospital. In this study the primary objective is to assess efficacy of Acyclovir in control of symptoms in patients with Menieres disease specially their vertigo attacks. Inclusion criteria would be patients willingness to participate in the study and follow ups, being 18 years old or older, having at least 2 vertigos per month each at least 20 min, interfering with function, and not on medication for Menieres disease for at least 3 months before the trial. They should not have any history of allergy to Acyclovir, renal insufficiency or Creatinine above 1.5 mgdl, hepatic enzymes more than three times normal, serious uncontrolled illness, be pregnant or nursing or have previous surgeries on Endolymphatic Sac. Participants will be randomly placed in 2 different arms getting either Acyclovir 400 mg or placebo inert ingredient. They will take the medication for 10 days 5 times a day, then 3 times a day for next 10 days, and 2 times a day for the last 10 days. Patients will report changes in their symptoms 10 days after initiating the drug and in 1, 3, 6 month intervals. 