Aims: To compare the number of comorbidities and the prevalence of five specific comorbidities in people who have temporomandibular disorders (TMD) with or without myofascial pain. Methods: This cross-sectional study included 180 patients seeking TMD treatment in Boston and Montreal hospitals. A selfadministered questionnaire was used to collect information on sociodemographic and behavioral factors, as well as the presence of the following five comorbidities: migraine, chronic fatigue syndrome, irritable bowel syndrome, interstitial cystitis, and restless leg syndrome. TMD was diagnosed using the Research Diagnostic Criteria for TMD. Chi-square and Student t tests were used for categorical and continuous variables, respectively, to test for differences between myofascial (n = 121) and nonmyofascial (n = 59) TMD groups. Multiple logistic regression analysis was used to compare the type and number of self-reported comorbidities in both groups, controlling for confounding variables. Results: The following were found to be significantly higher in the myofascial TMD group than in the nonmyofascial TMD group: self-reported migraine (55% vs 28%, P = .001), chronic fatigue syndrome (19% vs 5%, P = .01), and the mean total number of comorbidities (1.30 vs 0.83, P = .01). Conclusion: Individuals with myofascial TMD had a higher prevalence of self-reported migraine and chronic fatigue syndrome than those with nonmyofascial TMD. Keywords: central sensitivity syndrome, comorbidity, myofascial pain, overlapping conditions, temporomandibular disorders