Twenty-six patients suffering from migraine with aura and without aura were examined using somatosensory evoked potentials (SEPs) during the intercritical phase. The mean amplitude of the prerolandic component was significantly reduced in migraine patients with and without aura on the right hemisphere; the ratio between the parietal N20/P25 and the prerolandic P22/N30 was significantly enhanced in migraine groups over the left and the right hemisphere. A significant interside asymmetry of the N30 amplitude was observed in the migraine with aura group in comparison with control subjects. The occurrence of SEP abnormalities was not correlated with the age of the patients, with illness duration or with the frequency of migraine attacks. SEP abnormalities observed in migraine with and without aura may have an underlying primary neural disorder probably based on a chronic dopaminergic dysfunction.