Restless legs syndrome (RLS) is characterized by disturbing leg sensations associated to sleep complaints and excessive daytime somnolence. In the elderly, it affects 10 to 35%. Our objective was to determine the prevalence of RLS in institutionalized elderly, analyzing its relationship with clinical, laboratorial and neurophysiological features. We conducted a cross-sectional study of all the subjects under treatment on a chronic-care geriatric service by using face-to-face interviews, which include sleep complaints, the Epworth Sleepiness Scale and standardized questions addressing the four minimal criteria for RLS. The patients with RLS diagnosis received neurological examination, laboratorial tests and three of them, neurophysiological evaluation. The prevalence of RLS was 15.6%. Women were more affected and sleep complaints were frequent. There was no significance on other clinical, laboratorial or neurophysiological findings. We conclude that RLS is a prevalent condition in elderly, may lead to sleep complaints and is often underdiagnosed.