In this paper I examine the traditional postpartum beliefs and practices which still exist in northern Thailand today. The paper is based on qualitative research involving in-depth interviews with 30 women in Chiang Mai province. Beliefs and practices remain an essential part for postpartum care for women and have important consequences for women's health and wellbeing in northern Thailand. Many Thai women see their reproductive health problems as the consequence of inadequate postpartum practices. Thai women also believe that the effects of postpartum taboos would continue for the rest of their lives. Although the traditional postpartum beliefs and practices abound, the level of adherence differs according to the social structure of the women and their families. Poor rural women seem to hold on to their traditions more strongly than their urban counterparts. Urban middle class women in particular embody modernity in their thinking and behaviours concerning postpartum practices. But modernization has brought with it medical dominance. Due to their medical knowledge, doctors retain authority over both knowledge and status. The consequence of this dominance is the attempt to dismiss local traditional knowledge and practices. Although the pattern of traditional postpartum beliefs and practices is changing, it is still observed in northern Thailand. I contend that postpartum care for women incorporates local traditions so that women's health can be optimized at the time when they are in the most vulnerable stage of their lives.