Four hundred thirthy one epileptic patients, aged 10 years or more old, have been studied in the neurology clinic of Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da U.S.P., from February to July, 1981. The authors selected 119 patients aged between 13 to 45 years, that presented periodic menstrual bleeding and at least, one epileptic seizure a month. The patients were divided in two groups, the first constituted of 36 patients with catamenial seizures and the second one with 83 patients showing non catamenial seizures. The authors compare the number of pictures suggestive of "organic lesions" found in both groups. The statistical analisis shows that there are no differences between the two groups. The authors registered the EEG findings of these patients.