This paper reviewed the literature evaluating medical treatment in patients with vertigo and a MEDLINE literature search for the years 1966-2002 was performed using these search terms: labyrinth disease, drug therapy, clinical trials or randomized controlled trials. The search identified 351 clinical trials including 84 randomized controlled trials (RCTs) specifically examining drug therapy for vertigo published between 1966-2002. There were a large number of articles describing the effectiveness of cardiovascular agents, histamine antagonists and/or cholinergic antagonists in treating vertigo. Thirty-eight studies involving scopolamine and 31 studies involving betahistine were identified, 17 and 10 of which were RTCs, respectively. Only 3 of 13 studies involving steroids and 3 or 13 studies involving diuretics were RTCs and there was no RTCs concerning the use of aminoglycosides. Only one review assessed the effects of betahistine in Meniere's disease was identified by searching the Cochrane Library. This review, however, concluded that there was insufficient good evidence on the effect of betahistine in Meniere's disease, because there were no trials with a low risk of methodological bias. Based on these results, a large randomized clinical trial using the highest level of diagnostic criteria and outcome measures should be required to obtain better evidence regarding medical treatment on vertigo.