Restless legs syndrome (RLS), characterized by leg restlessness and dysesthesia predominantly at night and at rest, disrupts sleep and quality of life. The reported prevalence of RLS is 2% to 5%. Although a relation between RLS and coronary artery disease has been suggested, the prevalence and clinical significance of RLS in coronary artery disease patients remain unknown. We enrolled coronary artery disease patients who underwent percutaneous coronary intervention. Patients with RLS were identified according to international criteria. Subjective sleepiness, sleep quality, and health-related quality of life were assessed using the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and Short Form-8, respectively. Among 326 patients with coronary artery disease, 26 (8.0%) had RLS. There were no significant differences in characteristics between patients with and without RLS. Sleep quality and quality of life were more disrupted in patients with RLS (Pittsburgh Sleep Quality Index score, 7.4 ± 2.4 vs 5.6 ± 2.5, p <0.001; physical component summary and mental component summary scores of Short Form-8, 39.6 ± 1.8 vs 43.5 ± 0.5, p = 0.042 and 45.2 ± 8.4 vs 48.4 ± 7.4, p = 0.037, respectively), despite no significant difference in Epworth Sleepiness Scale score (8.2 ± 5.1 vs 7.1 ± 4.8, p = 0.293). In multiple linear regression analyses, RLS was independently associated with Pittsburgh Sleep Quality Index (β = 0.174, p <0.001), physical component summary (β = -0.127, p = 0.029), and mental component summary (β = -0.113, p = 0.042) scores. In conclusion, in patients with coronary artery disease, the prevalence of RLS was relatively high compared to that reported in the general population. The presence of RLS was associated with disrupted sleep quality and health-related quality of life in coronary artery disease patients.