videonystagmography (VNG) is one the main tests which are applied to diagnose the cause of vertigo. After primary examinations by a specialist, if they are suspected to dysfunctions in balance structures in the inner ear and its connections to the central nervous system, VNG test is recommended. This test is usually conducted and interpreted by an audiologist. In this test, abnormalities in different eye movements which are resulted from inner ear disorders are evaluated. Moreover, positional vertigo and vestibular nerve function are evaluated. After diagnosis of patient’s vertigo cause, appropriate treatment option is recommended. Without this test, a definitive diagnosis of the exact cause of vertigo is impossible in many patients.