A retrospective study was conducted on 1300 women suffering from migraine without aura referred to the Headache Centers of Parma and Pavia from 1984 to 1990. All the data concerning their reproductive life, and the modifications induced by it on the course of headache were obtained from record-charts. Migraine frequently started at menarche (10.7%); in 60% of cases the migraine attacks occurred mostly or exclusively in the perimenstrual period, in 67% of cases disappeared during pregnancy, and in 24.1% significantly (P < 0.0001) worsened with "pill" intake. This study also designated a migraine subgroup which is more influenced by changes in sexual hormones, i.e. migraine with onset at menarche. This form of migraine shows more frequently a menstrual periodicity, and usually improves during pregnancy. Furthermore, menstrual migraine patients show social and cultural characteristics with distinguish them from other women.