To determine if people with migraine are at increased risk of certain vascular diseases, a retrospective cohort study of the middle-aged and elderly parents of migraine patients was carried out. Questionnaires about diseases in each of their parents were sent to migraine patients who had one parent with and one without migraine. Parents with migraine were compared to parents without migraine of the same sex within narrow age groups. The frequency of high blood pressure is estimated to be 1.7 times greater in people with migraine than in people without (p < 0.05). The risk of heart attack also is increased for people with migraine and is most evident below age 70 years, but the risk of stroke is not appreciably increased. For each sex, people with migraine tend to die at younger ages than people without migraine.