The present study was undertaken to develop the method of diagnosis of vertigo with analysis of nystagmus in rapid eye movement (REM) sleep. Seven inpatients with vertigo (2 males and 5 females; 39.7±12.7 years (mean±SD)) participated. They underwent electronystagmography assessment in their night sleep. During Non-REM sleep, the nystagmus of all patients with peripheral vertigo disappeared except stage 1. During REM sleep, rapid eye movements (REMs) of all patients were recorded. Almost all of the patients with peripheral vertigo showed a larger value of REM density towards the direction in the awake state than the other. The findings of our study led us to hypothesize that the analysis of eye movements during nocturnal sleep may be useful for evaluating the vestibular nuclei function.