Many women with migraine, especially those with a history of menstrual migraine, experience an exacerbation as they approach menopause. During this time, the orderly pattern of estrogen and progesterone secretion is lost. The fluctuating and falling levels of estrogen during the perimenopausal years may increase the frequency and severity of migraine. In such women, restoration and stabilization of estrogen levels within the physiologic range are likely to diminish the migraine. Although continuous combined hormone replacement therapy with estrogen and progesterone is becoming increasingly popular for postmenopausal women, many women are still prescribed cyclic replacement initially. For the woman who is susceptible to fluctuations in estrogen and progesterone, initiation of cyclic therapy after menopause may exacerbate migraine. This could occur in a woman who noted an improvement in migraine after menopause with complete cessation of menses and stable levels of estrogen. For the woman with migraine, continuous combined estrogen and progesterone (or estrogen alone, if the uterus has been removed) replacement is the preferred therapy. This can be achieved with a 50-microg/day estrogen skin patch such as Estraderm or Vivelle twice weekly or Climara once weekly, or with an oral estrogen such as Premarin, Ogen, or Estrace, with half the daily dose given every 12 hours to maintain optimal stability. In the presence of a uterus, progesterone should be added, either as low-dose medroxyprogesterone acetate (Provera) 2.5 mg every evening or micronized progesterone (Prometrium) 100 mg every evening. The usual contraindications to hormone replacement therapy may be applied to women with migraine.