A neuropsychologic test battery was administered to 16 outpatients with classic migraine and 15 outpatients with common migraine between attacks and 15 matched nonheadache volunteers. Both migraine groups demonstrated significantly greater average neuropsychologic impairment and more self-reported cognitive difficulties than the nonheadache control group. Current medication use did not explain the relative neuropsychologic impairment. Both classic and common migrainous disorders seem to involve a disturbance of cerebral function beyond the attack itself.