Three groups of patients, long-time sufferers from classic migraine, common migraine, and cluster headache respectively, and three control groups, age- education- and sex-matched, underwent a set of neuropsychological tests and tachistoscope tasks in order to evaluate cognitive functions and interhemispheric balance. Migraineurs and cluster headache patients were selected on the basis of the constant (90%) unilaterality of both pain and focal neurological deficits. No significant differences emerged between patients and controls in any of the neuropsychological and tachistoscopic tasks administered, thus indicating that between attacks of migraine as well as of cluster headache no evidence of cortical dysfunction is detectable.