Aims: To investigate the prevalence of temporomandibular disorders (TMD) in the 46-year-old cohort subjects from the Northern Finland Birth Cohort 1966 (NFBC 1966). Methods: Altogether, 1,962 subjects (1,050 women, 912 men) participated in a clinical medical and dental examination and responded to questionnaires in 2012 to 2013. The stomatognathic examination was performed according to a modified protocol of the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Pearson's chi-square test and Fisher's exact test were used to analyze the signs of TMD between genders, and logistic regression models were used to analyze the relationship between self-reported pain associated with TMD and modified DC/TMD protocol (P .05). Results: Of the subjects available for analyses, 18.5% responded positively to the self-reported screening question for pain related to TMD. The most common signs of TMD were clicking in the temporomandibular joint (TMJ) (26.2%) and palpation pain in the masticatory muscles (11.2%). Women had signs of TMD more often than men (P .05). The most common diagnosis was disc displacement with reduction (7.0%). Myalgia, arthralgia, disc displacement with reduction, and degenerative joint disease diagnoses were statistically significantly more common in women than in men (P .05). The prevalence of TMD signs among the cohort subjects was 34.2%. Conclusion: The most common sign of TMD was clicking in the TMJ and the most common TMD diagnosis was disc displacement with reduction. The prevalence of TMD signs among the examined cohort subjects was 34.2%. TMD was diagnosed in women more often than in men. The results are comparable with other corresponding population-based studies in adults. Keywords: cohort study, DC/TMD, NFBC 1966, temporomandibular disorders, TMD