Dizziness is dangerous sign. The proofs are presented that it is always related to vestibular disorder, even if it is of visual origin. Vestibular system does not resemble any other type of analyser. It has six peripheral sensors: gravitation, movement, acoustic, vibration, magnetic impulse and metabolism. Being sensory system it has at the same time integrative function. Together with hearing, vision and proprioception it provide space orientation and interaction. Vestibular cortical projection has four representations: in vestibular, somatosensory, visual and acoustic cortical areas. It has tight connections with motor, vegetative and limbic brain systems. Vestibular disorders are often hidden after vegetative or limbic manifestations. Vestibular evoked potentials are presented from the evidence-based point of view as the only method for vestibulo-cortical projection studies. Objective methods for studies of vestibulo-motor, vestibulo-vegetative and vestibulo-limbic projections are described with their positive and negative sides. Wide spectrum of nosologies: starting with kinetosis and Meniere disease and ending with chronic fatigue and cardioneurosis.