The treatment of patients suffering with menstrual migraine is sometimes a difficult and frustrating problem for the physician. As many menstrual migraine headaches are refractory to abortive therapy, prophylactic therapy is often needed. Ergonovine maleate, an ergot derivative with vasoconstrictive properties, has been used with some success in migraine headache patients. Forty patients who were treated with intermittent prophylactic ergonovine were studied over six months. The patients ranged in age from 22 to 40 years, and all suffered with menstrual migraine headaches which were refractory to abortive therapy. Each patient took ergonovine maleate 0.2 mg three to four times daily during menses and recorded headache occurrence and severity. After three months, 24 patients (60%) reported significantly less severe attacks, six patients (15%) reported less frequent headaches and 14 patients (35%) reported no improvement. After six months there was a decrease in effectiveness with 20 patients (50%) reporting significantly less severe headaches and two patients (5%) reporting less frequent headaches. This limited study suggests that ergonovine maleate may be of value in the treatment of difficult menstrual migraine patients.