Headache patients frequently contact physiotherapists and manual therapists. In case of elderly patients with unilateral headache, neck and facial pain clinical practice guidelines recommend further referral for medical investigation to exclude red flags. The present patient was seen in a multidisciplinary headache clinic. He was referred by the neurologist (headache specialist) for physiotherapeutic assessment after screening for red flags, including giant cell arteritis (GCA). After first assessment, GCA was considered unlikely, since the sedimentation rate, as a marker for inflammation, was only slightly elevated. The purpose of the referral was to exclude cervicogenic headache (CEH) and to explore physical treatment as a therapeutic option. Physiotherapeutic assessment consisted of a history taking on CEH signs (Sjaastad criteria, 1998), followed by cervical spine assessment including tests for neck mobility, joint pain, and endurance of the short neck flexors. The patient's history revealed no specific signs of CEH and cervical spine assessment was negative. In consultation with the neurologist, the diagnosis of CEH was abandoned. Since palpation of the temporal artery proved to be painful, laboratory examination and biopsy of the temporal artery were thereafter performed, this time revealing GCA. Appropriate treatment (high dose steroids) was initiated promptly, with a good clinical evolution. The presented case shows the potential of a multidisciplinary collaboration in the clinical diagnostic work-up of patients with head and neck pain.