The pathophysiology of vestibular migraine (VM) is still a matter of speculation. The most promising hypothesis is the release of neuropeptides such as calcitonin gene-related peptide (CGRP) that is not only pivotal in migraine headache but also modulates the activity of central vestibular structures. Clinical examination of patients with acute VM has clarified that the vast majority of patients with VM suffer from central vestibular dysfunction. Neither in the acute episode nor in the interval is there any specific testing abnormality in vestibular migraine. However, laboratory testing can be useful to exclude other diseases and to reassure the patient. It is important to take note that minor signs of peripheral and central vestibular dysfunction are not uncommon in patients with vestibular migraine in the symptom-free interval. In this chapter, findings in the symptom-free interval and during the acute episode of VM are summarized.