Periodic alternating nystagmus is a rare central nervous system disorder in which the eyes undergo a horizontal jerk nystagmus that periodically reverses direction. A patient with a hypoplastic cerebellum and enlarged cisterna magna exhibited transient periodic alternating nystagmus following an attack of Ménière's disease. We hypothesize that in susceptible individuals with cerebellar disturbances, periodic alternating nystagmus may be transiently induced by vestibular stimuli.