The present study investigated whether administration of percutaneous estradiol for the 7 days encompassing menstruation (the paramenstruum) would be effective in alleviating menstrual migraine. The study was a double-blind cross-over placebo comparison of percutaneous estradiol in gel form. Twenty-two women who suffered from regular recurring menstrual migraine were studied during 2 assessment menstrual cycles, 4 treatment cycles (2 of estradiol gel, 2 of placebo gel), and 1 follow-up (no treatment) cycle. Women completed daily records of the occurrence and severity of migraine and medication used. Eighteen women completed the study. There was a significant reduction in the frequency of migraine in the paramenstruum and in the amount of medication taken during use of percutaneous estradiol. Women expressed a significant preference for continuation of therapy with percutaneous estradiol.