Aims: To describe the characteristics of headaches attributed to temporomandibular disorders (TMD) and assess the effects of two management strategies used for the management of TMD on headache intensity and frequency. Methods: The initial sample (n = 60) of this randomized controlled trial comprised patients with masticatory myofascial pain according to the Research Diagnostic Criteria for TMD (RDC/TMD), and headache. The patients were divided into two groups: group 1 received only counseling for behavioral changes, and group 2 received counseling and an occlusal appliance. A 5-month followup period included three assessments. TMD-related headache characteristics, eg, headache intensity (scored on a visual analog scale [VAS]) and frequency were measured by a questionnaire. Two-way analysis of variance, chi-square, Friedman, and Mann-Whitney tests were used to test for differences considering a 5% significance level. Results: The main clinical features of headache attributed to masticatory myofascial pain were the long duration (≥ 4 hours), frontotemporal bilateral location, and a pressing/tightening quality. Forty-one subjects (group 1, 17 subjects; group 2, 24 subjects) were included in the final analysis. There was a reduction in headache intensity and frequency, with no significant differences between groups (P > .05). The mean (± SD) baseline VAS was 7.6 (± 2.2) for group 1 and 6.5 (± 1.6) for group 2; final values were 3.1 (± 2.2) (P .001) and 2.5 (± 2.3) (P .001), respectively. Conclusion: Headache attributed to masticatory myofascial pain was mainly characterized by long duration, frontotemporal bilateral location, and a pressing/tightening quality. Also, counseling and behavioral management of masticatory myofascial pain improved headache, regardless of the use of an occlusal appliance. Keywords: diagnosis, myofascial pain, occlusal splint, secondary headache, temporomandibular joint disorders