Background Chronic headache is associated with disability and high utilisation of health care including complementary and alternative medicine (CAM). Findings We investigated self-reported efficacy of CAM in people with chronic headache from the general population. Respondents with possible self-reported chronic headache were interviewed by physicians experienced in headache diagnostics. CAM queried included acupuncture, chiropractic, homeopathy, naprapathy, physiotherapy, psychological treatment, and psychomotor physiotherapy. Sixty-two % and 73% of those with primary and secondary chronic headache had used CAM. Self-reported efficacy of CAM ranged from 0-43% without significant differences between gender, headache diagnoses, co-occurrence of migraine, medication use or physician contact. Conclusion CAM is widely used, despite self-reported efficacy of different CAM modalities is modest in the management of chronic headache.