Objective The aim of this study was to estimate the prevalence of signs and symptoms of temporomandibular disorders (TMD) in patients with primary headaches attended in a tertiary neurology ambulatory.Method Authorized by the Ethics Committee, the present cross-sectional study was conducted with a random sample of patients screened for orofacial pain and primary headaches at a tertiary hospital in Northeast of Brazil.Results The sample consisted in 42 patients with primary headache, 59.5% male. The prevalence of > 6 TMD signs and symptoms was 54.8%. In those patients with migraine TMD was present in 71.4% and in tension-type headache in 38.1% (p = 0.030; OR = 4.1). TMD was related to the clinical status of headache associated or attributed to medication overuse (p = 0.001).Conclusion TMD has a high prevalence in patients with primary headaches (54.8%). Special attention must be given to patients with migraine and headache associated or attributed to medication overuse.