Eighty subjects‐30 migraineurs during the attack, 30 patients in the interictal period, and 20 healthy volunteers‐were studied using two technologies for functional assessment: transcranial Doppler ultrasound and magnetoencephalography. Transcranial Doppler studies showed an increased mean flow velocity at rest (p < 0.05) in the middle cerebral artery on the side of the headache and a decreased vasomotor response to C02 (p < 0.001) on the same side compared to control subjects. Biomagnetic measurements of somatosensory evoked fields of 11 patients and 11 control subjects in this study did not demonstrate differences between migraineurs and the control group in current flow or latency measures. The data from this study tend to support the hypothesis of vascular disease as a primary underlying deficit in migraine.