OBJECTIVE: To investigate the presence of restless legs syndrome (RLS) and the quality of sleep in a population of type 2 diabetic patients. RESEARCH DESIGN AND METHODS: The study population was composed of 100 consecutive patients regularly attending a diabetes clinic at the University Hospital of the Federal University of Ceará. The subjects' quality of sleep was assessed by the Pittsburgh Sleep Quality Index, and excessive daytime sleepiness (EDS) was measured by the Epworth Sleepiness Scale. The RLS was diagnosed using the four minimum criteria defined by the International Restless Legs Syndrome Study Group. Other relevant clinical and laboratory parameters were obtained by interview and chart review. RESULTS: RLS was found in 27% of patients. Poor sleep quality was present in 45% of cases and was associated with age (P = 0.04), peripheral neuropathy (P = 0.001), and RLS (P = 0.000). EDS was found in 26% of patients. Logistic regression analysis revealed an association between RLS and peripheral neuropathy (odds ratio 12.85 [95% CI 2.83-58.40], P = 0.001). CONCLUSIONS: RLS is common in type 2 diabetic patients and can be a major cause of sleep disruption in these patients.