Migraine is a periodic disorder with a worldwide prevalence of 5-19%. This study raises the hypothesis of a sex-influenced genetic model of migraine transmission. That migraine may be sex-influenced (autosomal dominant in females and autosomal recessive in males) is supported by such evidences as: (1) familial hemiplegic migraine, subtype from migraine with aura, being dominantly assigned to autosomal chromosome 19p, 1q, and 2q; (2) a male to female prevalence of 1:2-4; (3) primarily young age of onset; (4) provocation by pharmaceutical contraception; (5) induction by menstruation; (6) self-limitation after menopause; and (7) only female migraineurs in some migraine families. Female sex hormone in the migraineur may be the key factor, comparable to the male sex hormone: androgen, in the genetic baldness. Migraine appears caused by a multi-factor inheritance with higher rates among females than males, and influenced by environmental and cultural factors.