The clinical distinction between migraine without aura and tension headache is more difficult in young children than it is in adults. The objective of this study was to examine the usefulness of topographic EEG mapping, as one method among other diagnostic techniques, for establishing a diagnosis. The clinical diagnosis of tension headache and migraine in children between 6 and 15 years of age was established according to criteria of the International Headache Society classification. Children with migraine and tension headache were examined during and between attacks. EEG mapping showed lateralized parietal diminution of alpha-power more frequently during an attack of migraine than during tension headache, which regressed between attacks. Compared to other methods, such as visual evoked potentials, EEG mapping may have the advantage of helping to diagnose each single headache, which could be useful in patients with combined headaches.