Background: The primary morbidities of restless legs syndrome (RLS) involve sleep loss, extreme discomfort, and disruption of normal activities. Although the condition is not life-threatening, assessing the disease burden and the impact of RLS on quality of life (QOL) is critical for evaluating treatment benefits. Objective: The purpose of this study was to assess the impact of RLS on QOL. Methods: in this subanalysis of a specific validation study, the SF-36 (Medical Outcomes Study 36-Item Short Form health survey) was administered to 85 patients with primary RLS who had been referred to a sleep-medicine clinic. The scores were compared with published norms for the general population (N = 2474). Results: The majority (63.5%) of RLS patients were women the mean (SD) age was 62.4 (14.0) years 67.1% of patients experienced RLS symptoms almost daily The RLS group, particularly patients with more severe RLS, reported significant deficits (10-40 points on 100-point scales) in physical functioning, role-physical, bodily pain, general health, vitality, social functioning, and role-emotional compared with the general population. The RLS sample had significantly lower scores (worse QOL) on all 8 scales of the SF-36 compared with patients with hypertension (P < 0.01); compared with patients with other cardiovascular conditions (ie, congestive heart failure, myocardial infarction within the past year, and angina), the RLS group had lower scores on 6 of the 8 scales. RLS patients had lower scores on 7 of 8 scales compared with diabetes patients, and on 4 of 8 scales compared with osteoarthritis patients. Conclusions: Comparison of the SF-36 scores of patients with RLS and the normative general population suggests that the disorder has a significant impact on patient QOL. Copyright (C) 2004 Excerpta Medica, Inc.