No reliable estimates of headaches following catheter-based cerebral angiography are available. We performed an observational cohort study to ascertain the frequency and type ofheadaches following catheter-based cerebral angiography. Consecutive patients who underwent cerebral angiography through the transfemoral (or infrequently radial) route were included. Each patient underwent a brief neurological assessment after the procedure and more detailed assessment was performed if any patient reported occurrence of a headache. The headaches were classified as migraine if the diagnostic criteria specified by International Headache Society were met. The headache severity was classified using a visual numeric rating scale and time to reach pain free status for 2 consecutive hours was ascertained. Migraine headaches occurred in 5 (3.1%, 95% confidence interval [CI] 1.0-7.2%) of 158 patients who underwent cerebral angiography. The median severity of migraine headaches was 10/10 and time to resolution of headaches was 120 minutes (range 60-360 minutes). Migraine headaches occurred in 4 (18.1%, 95% CI 5.2-40.3%) of 22 patients with a history of migraine and 4 (23.5%, 95% CI 6.8-50%) of 17 patients with regular migraine headaches (≥1 episodes per month). Headaches occurred in 6 (3.8%, 95%CI 1.8-8.0%) patients who did not meet the criteria for migraine headaches. We provide occurrence rates of migraine headaches, an under-recognized adverse event, in patients undergoing catheter-based cerebral angiography.