Objective. The objective of this study was to evaluate whether sleep dysfunction is a risk factor for burning mouth syndrome (BMS). Study design. An age-and sex-matched case-control study of patients with BMS and controls with various oral conditions was conducted. A numerical rating scale for oral discomfort and the sleep scale from the medical outcomes study were used for measurements, and statistical analyses included use of logistic regression models. Results. The odds ratios for lowest versus highest quartiles were sleep disturbance (OR = 9.7, P=.0095), sleep problems index (SLP) 6 (OR = 7.5, P=.032), and SLP9 (OR = 27, P=.0058), which remained significant after controlling for age and number of sedating medications. Conclusions. Findings from this cross-sectional study, although unable to establish a causal relationship, demonstrate that patients with BMS report a greater degree of sleep problems as compared with controls, and suggest that sleep dysfunction may be a risk factor for BMS and a possible target for treatment. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112: 203-208)