The Copenhagen acute headache clinic offered an opportunity to record EEG during migraine attacks in eleven patients with common migraine and ten patients with classical migraine. The median duration of the attacks was 9 h in common migraine. Three patients were studied during prodromes of classical migraine and seven in the early headache phase. The EEG was recorded in the resting state, during hyperventilation and during photic stimulation. No abnormalities were encountered in patients with common migraine nor in eight patients with classical migraine. In two patients with classical migraine mild abnormalities were seen during prodromes and in the early headache phase, but they were also present at a control EEG taken outside an attack. The present study indicates that migraine attacks are rarely associated with EEG abnormalities.