BACKGROUND: Given the safety concerns regarding pharmacological agents, and the considerable impact of headache and migraine on the sufferer's quality of life, many people seek other treatment options beyond conventional medication and care to address their symptoms; this includes complementary and alternative medicine (CAM). Some CAM interventions have shown promising results in clinical trials of headache and migraine management. Nonetheless, there has been little research exploring the reasons for using CAM, and the types of CAM used, among this population. OBJECTIVE: The study aimed to answer the following questions: (1) Which CAM modalities are used most frequently among migraine/headache sufferers? and (2) What are the self-reported reasons for CAM use among migraine/headache sufferers? METHODS: This secondary analysis of data from the 2012 U.S. NHIS (a national cross-sectional survey) examined the use of CAM among migraine/headache sufferers, including the main reasons related to CAM use. Data were weighted and analyzed using STATA 14.0. RESULTS: The sample of 34,525 adults included 6558 (18.7%) headache/migraine sufferers. Of the headache/migraine sufferers, a substantial proportion (37.6%, n = 2427) used CAM for various conditions; however, CAM use specifically for headache/migraine was much less prevalent (3.3%, n = 216). Of those who used CAM for headache/migraine, about half used CAM in conjunction with prescription (47.8%, n = 100) or over-the-counter medication (55.1%, n = 113). As severity of headache/migraine increased so did the likelihood of using CAM (severe migraine odds ratio [OR] = 2.32; 95% confidence interval [CI]: 1.41, 3.82; both recurring headache/severe migraine OR = 3.36; 95% CI: 2.08, 5.43; when compared to those with recurring headache only). The most frequently used CAM modality among all headache/migraine sufferers (N = 6558) was manipulative therapy (22.0%, n = 1317), herbal supplementation (21.7%, n = 1389) and mind-body therapy (17.9%, n = 1100). The top 3 reasons for using CAM for headache were general wellness (28.7%, n = 60/209), improving overall health (26.8%, n = 56/209), and reducing stress (16.7%, n = 35/209). CONCLUSIONS: Although CAM is used by many sufferers of headache/migraine, the use of CAM specifically for the treatment of headache/migraine is relatively low in the United States. The study also assesses the key differences of CAM use among headache/migraine sufferers in NHIS 2012 compared with those in NHIS 2007, and identifies shortfalls in the evidence-base of several CAM modalities used by U.S. adults for headache/migraine. This information may assist health providers and consumers in making informed decisions about the safest and most appropriate approach to managing headache/migraine.