This paper represents a review of current opinion and information on the effective diagnosis of restless legs syndrome (RLS) in a primary care setting. RLS can be a distressing condition--it can cause serious sleep disturbance and has a significant impact on quality of life comparable to that of depression or type 2 diabetes. The prevalence of adults whose RLS is severe enough to warrant medical advice has been estimated to be approximately 3%, but only a small proportion of these patients currently report having been diagnosed in primary care, despite stating that they have presented to their GP. The benefits of increased understanding of the symptoms of RLS and how patients present in primary care are discussed, with emphasis on how this will help GPs more effectively diagnose and manage the patients affected. Guidelines on how to diagnose RLS in a primary care setting are given--when a patient presents with sleep disturbance, RLS should be routinely considered and, where existing, be readily diagnosed in a primary care setting on the basis of the patient's clinical history, a physical examination and with the aid of four questions based on the International RLS Study Group (IRLSSG) four essential diagnostic criteria.