Guidelines recommend imaging only headache patients with sinister features in the history or on examination. We prospectively collected data on imaging newly presenting patients to a UK headache service. CT and MRI results were classified as normal or showing an insignificant or significant abnormality. Over 5 years, 3,655 new patients (69% female; mean age 42.0 years) with headache disorders were seen. Five hundred thirty (14.5%) underwent imaging with large differences in the proportion referred by each consultant. There were more insignificant abnormalities on MRI (46%) than CT (28%). There were 11 significantly abnormal results (2.1% of those imaged). Significant abnormalities were found in patients diagnosed with migraine in 1.2% and in 0.9% of those with tension-type headache. Significant abnormalities in those suspected to have an intracranial abnormality occurred in 5.5%. This supports the practice of selecting patients with suspicious findings for imaging, rather than imaging all patients.