The first (or menstrual) and fourth (or premenstrual) week of the menstrual cycle may be associated with many suicide attempts in women. The study sample included 113 Spanish women who attempted suicide and contacted an emergency service. Inclusion criteria were as follows: fertility; regular menstrual cycles; lack of oral contraceptives; and willingness to see a psychiatrist. The incidence of suicide attempts in the first week (36%) was significantly higher than that in the remaining weeks (second week, 19%; third week 16%; fourth week, 29%). A correspondence analysis suggested that suicide attempts were associated with differences in demographics and clinical profiles. In particular, suicide attempts in the third week were correlated with a severe history of psychiatric problems and a lower level of education. The limitations of this study are its exclusiveness to hospitalized cases and its use of patient reports to date menstruation.