INTRODUCTION: Restless legs syndrome (RLS) is characterized by an uncomfortable sensation on the legs, which causes the urge to move the legs. The main cause is unknown but there are many risk factors, including geographical properties and high altitude. Our objective was to explore the frequency of RLS in aircrew. METHODS: There were 301 Turkish aircrew who were admitted to Istanbul Medipol University Hospital Neurology Department for periodic examinations and 272 healthy (non-aircrew) subjects included in the study. The International RLS Study Group's Questionnaire and the International RLS Study Group Rating Scale (IRLSSGRS) were used to evaluate RLS. The participants filled the RLS questionnaire and then both groups were divided into two subgroups as having RLS or not. The subjects' years in the profession, average flight duration in a month, daily sleep duration, smoking, and coffee consumption were recorded. None of the subjects had previously been diagnosed with RLS. RESULTS: The frequency of RLS was 6.7% in the aircrew group and 7.9% in the control group, and there was no significant difference between the two groups. Age, gender, daily duration of sleep, smoking, coffee consumption, family history of RLS, being a pilot or a flight attendant, years in profession, and monthly flight hours were similar in aircrew with and without RLS. DISCUSSION: The RLS frequency in aircrew was similar to that of the control group. We can conclude flying at high altitude wasn't a risk factor for RLS.