Abstract The vestibular system is a phylogenetically old sensorimotor system whose function is to sense and compensate for movement. Specialized hair cells transduce the mechanical forces of angular and linear accelerations to neural discharges. These motion signals drive vestibuloocular and vestibulospinal reflexes that stabilize vision, adjust head and body posture, and maintain balance. The vestibulocerebellum plays a critical role in the calibration and plasticity of these reflexes. An acute lesion of one labyrinth causes vertigo and nystagmus, due to an abrupt imbalance in vestibular inputs, whereas bilateral lesions cause imbalance and loss of vestibular reflexes. Episodic vestibular syndromes can be distinguished by the duration of attacks and the context in which they occur. Common disorders include Ménière's disease, vestibular migraine, benign paroxysmal positional vertigo, and vertebrobasilar ischemia.