The RLS is an underdiagnosed condition, characterized by unpleasant sensations in the legs. Pathophysiological mechanisms may include iron deficiency as reflected by low serum ferritin levels and dopaminergic system dysfunction. The purpose of our study was to investigate the prevalence and characteristics of RLS in the elderly and the relation of serum ferritin levels with disease severity. Ambulatory 1012 (621 women, 391 men, mean age: 73.51 +/- 7.12 years) consecutive patients above 65 years who admitted to our clinic for any reason were evaluated according to the International RLS Study Group (IRLSSG) criteria: 103 patients (74 women, 29 men, mean age: 72.43 +/- 6.31) (10.18%) had RLS diagnosis. Only 9 of them had known RLS. The duration of symptoms was 4.80 +/- 4.65 years and 27 patients (26.2%) had positive family history. The average of serum ferritin levels was 39.13 +/- 23.74 ng/ml and 71 patients (68.9%) had serum ferritin levels <= 50 ng/ml. The disease severity was evaluated with IRLSSG rating scale. Patients were classified as severe-very severe group (n = 49) and mild-moderate group (n = 54). The ferritin levels of severe-very severe disease group were lower than those of mild-moderate disease group (26.01 +/- 15.82 ng/ml versus 49.87 +/- 23.24 ng/ml, p < 0.001). Our data show that RLS is very common in the elderly and the disease is more severe in patients with lower ferritin levels. (C) 2011 Elsevier Ireland Ltd. All rights reserved.