ObjectiveThe aim of this study was to design and use a headache diary in patients with frequent tension-type headaches (TTH). Another aim was to assess the relationship among oral behaviors, range of motion, and tenderness to palpation of the craniomandibular muscles. MethodsThirty-four patients participated in this prospective observational study for a 3-month period at the Adavall Clinic for Physiotherapy and Rehabilitation (Valladolid, Spain) in 2019. Oral behaviors were collected through the Oral Behavior Checklist in the Adavall-TTH diary. Range of motion was measured in the cervical region and in the temporomandibular joint. Tenderness to palpation was measured on 38 myofascial trigger points of the craniomandibular region. ResultsOral behaviors were directly related to the pain intensity of TTH, the number of days, and the headache diagnostic criteria. Cervical range of motion was indirectly related to the intensity of TTH and the number of days of TTH (from r = −0.341 to r = −0.418, P < .05). Tenderness to palpation was associated with intensity and different diagnostic criteria of TTH in different craniomandibular muscles (from r = 0.342 to r = 0.400, P < .05). ConclusionWe found associations between examination findings and TTH diagnostic criteria. The headache diary may be a useful tool in the diagnosis and management of TTH and for analyzing the relationship between oral activities and temporomandibular joint tenderness in TTH. Future research should test the validity and reliability of this diary.