Vertigo is not a disease, but a symptom. Therefore, the therapy of vertigo is primarily directed at eliminating the underlying cause. In about half of the cases the cause will not become apparent, however, and the therapy is doomed to be symptomatic. Several types of drugs have been found to have an anti-vertigo activity, e.g. antihistamines, calcium antagonists, anti-emetics. For the selection of vestibular depressants, the vestibular caloric test and the rotation test can be used. The duration of the nystagmus induced by rotation is the most useful parameter. The lag-period, the extent and duration of the vestibular effects can be determined and compared with that of other substances. A stronger action on a nystagmus does not necessarily mean a stronger anti-vertiginous action. The final proof of an anti-vertiginous activity can only be established in clinical studies in patients with vertigo.