The objective of this study is to determine whether spontaneous complaints about sleep or the legs could be used as potential indicators of restless legs syndrome (RLS) in primary care. A total of 351 general practitioners participated in the study. In a first historical patient identification phase, all patients with spontaneous complaints of sleep or leg symptoms over the previous year were identified. A control group without such complaints was identified. In a second prospective data collection phase, those who consulted a participating physician were interviewed to assess consensus diagnostic criteria of RLS. Severity was assessed with the International Restless Legs Syndrome Study Group severity rating scale. Of 1,405,823 patients consulting during the historical phase, a leg complaint was reported in 61,685 and a sleep complaint in 40,568. A total of 1,432 consulted during the prospective phase. A diagnosis of RLS was assigned to 42.6% of patients with leg complaints, 35.5% of those with sleep complaints, 54.9% of those with both complaints, and 12.9% of those with no complaints. Median RLS severity scores were 18.8 to 20.4. A total of 63.7% of patients were prescribed a venotonic, 43.7% a hypnotic, and 41.5% an anxiolytic. Complaints of sleep or leg symptoms are frequently associated with a diagnosis of RLS, and their presence should alert the physician to the possibility of a differential diagnosis of RLS.