BACKGROUND AND AIM: The few studies concerning the association between sleep disorders and functional dyspepsia (FD) have yielded inconsistent results. We compared the prevalence of sleep disorders in patients with FD and healthy controls, and evaluated whether FD was independently associated with sleep disorders, and the risk factors for sleep disorders in patients with FD. METHODS: This prospective, multicenter, cross-sectional study was conducted from August 2014 to December 2017 at 12 hospitals in South Korea. The inclusion criterion was the presence of FD (for ≥18 years) according to the Rome III criteria. Healthy controls were recruited from among patients who visited the Health Examination Center for check-ups. RESULTS: In total, 526 subjects were prospectively enrolled in this study (201 with FD and 325 healthy controls). The prevalence of sleep disorders was significantly higher among the patients with FD than among the healthy controls (41.8% vs 18.8%, P = 0.000). In a multivariate analysis, FD (odds ratio [OR] = 1.851; 95% confidence interval [CI] 1.194-2.870; P = 0.006), female sex (OR = 1.672; 95% CI 1.063-2.628; P = 0.026), and anxiety (OR = 3.325; 95% CI 2.140-5.166; P = 0.000) were independent risk factors for sleep disorders in the overall cohorts. In patients with FD only, low body mass index, heartburn, and anxiety were independent risk factors for sleep disorders in a further multivariate analysis. CONCLUSION: Sleep disorders were common in patients with FD. FD was significantly associated with sleep disorders in our patient population, irrespective of the presence of heartburn or psychiatric disorders.