The main goal of this open-label, prospective, non-controlled, non-interventional post marketing surveillance (PMS) study is to evaluate how pramipexole (PPX) treatment works when applied in actual practice. In actual practice patients who would have been excluded in the clinical registration studies of PPX in moderate to severe primary RLS (i.e. those with certain disease histories, co-morbidities and/or demographic characteristics) will also be treated with PPX. Thus, during this PMS study additional information on the efficacy and safety of PPX in those patients will be obtained. The objectives of this

PMS study are:

• To investigate the influence of Sifrol® (pramipexole) treatment on unpleasant sensory symptoms of RLS as measured with the short form of the McGill Pain Questionnaire.
• To assess if improvement of sensory symptoms correlates with overall RLS severity (IRLS) and with secondary symptoms like sleeping problems and daytime tiredness (items 1 & 6 from RLS-6).
• To evaluate if the treatment effect of Sifrol on overall RLS severity (IRLS) differs between patients with high pain scores and patients with lower pain scores.
• To compare GP and neurologist sites patient populations in terms of demographics, RLS severity at Visit 1 and treatment outcomes at Visit 3.
• To evaluate the development of behavioural changes under PPX treatment.