We evaluated the hormonal profile and the platelet function in a group of 20 patients with menstrual migraine and a control group of 10 healthy women. Plasma levels of estradiol, progesterone, FSH and LH, as well as betathromboglobulin, platelet factor 4 and platelet serotonin were measured in different phases of the menstrual cycle. The hormonal profile did not show significant differences between both groups. The patients with menstrual migraine had higher BTG, FP4 and serotonin levels in the premenstrual phase than the control group. The results of this study show that in premenstrual migraine a platelet hyperagregation develops during the premenstrual phase. This abnormality is not directly correlated with the hormonal fluctuations observed during the menstrual cycle.