Aims: To evaluate the impact of smoking on pain severity, psychosocial impairment, depression, anxiety, and sleep disturbances in a large sample of patients with temporomandibular disorders (TMD). Methods: A retrospective database review was performed on data from 3,251 patients with TMD, diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Pain severity ratings and psychometric data regarding impairment, sleep disturbance, depression, and anxiety were obtained. Differences between smokers and nonsmokers were evaluated by means of chi-square tests and independent samples t tests. Logistic regression models were used to study the impact of smoking, pain severity, and psychometric variables. Results: Of the total population, 42.5% comprised RDC/TMD group I (muscle pain), 25.3% comprised RDC/TMD group III (joint pain), and 32.2% comprised a mixed RDC/TMD group consisting of patients with both a group I and a group III diagnosis. Of the entire population, 26.9% admitted they were smokers. Even after controlling for relevant covariates, smokers reported significantly higher pain severity, impairment, anxiety, depression, and sleep disturbances than nonsmokers. Conclusion: Smokers with TMD reported higher pain severity than nonsmokers with TMD. These patients are at higher risk for factors that may adversely affect treatment outcomes. Keywords: anxiety, depression, nicotine, sleep disturbance, temporomandibular disorders