The purpose of the study was to explore the association between depressive symptoms and social support in Taiwanese women doing the month. A correlational survey design using the Postpartum Social Support Questionnaire (PSSQ) and the Edinburgh Postnatal Depression Scale (EPDS) to measure social support and postnatal depressive symptomatology was employed. Two hundred and forty postpartum women receiving care in two teaching hospitals in Taipei, Taiwan, aged between 20 and 35, with no peri-natal complications or previous psychiatric history, experiencing a normal spontaneous delivery of one full term healthy baby, were selected. Each was mailed the PSSQ and the EPDS as well as a short, semi-structured self-report questionnaire requesting demographic details and subjective data relating to the experience of doing the month and depressive symptoms during the fourth week following birth. One hundred and eighty six women (78%) returned questionnaires. Taiwanese postpartum women were less depressed when they stayed in their parents' home and had their own mothers take care of them. It was found that the greater the level of postpartum social support received by the women doing the month, the lower the risk of postnatal depressive symptoms experienced. Almost a quarter (24%) of the variance of the symptoms was attributed to dissatisfaction with parents' instrumental support and unwanted emotional support from parents-in-law. It is concluded that the ritual of doing the month provides valuable social support and may help to prevent postnatal depression in Taiwanese women.