If there is one aspect of midwifery practice that seems to en cap sul ate and reinforce physiological labour and birth, it is waterbirth. I used this term to include water immersion for labour and/or giving birth in water. It was introduced into UK labour wards in the late 1980s after pub licity from the Pithiers unit in France where Michel Odent practised. My memory of it goes back further to a book I read in the late 1970s by Leboyer, Birth without Violence. At the same time a Russian boat builder and visionary began pro­ moting waterbirth in the Soviet Union. He became convinced of the bene fits of water immersion as a means of maximising physiological potential, and his story is told by Sidenbladh (1983). These books have even greater reson­ ance now as the spectre of obstetric viol ence gets fresh exposure in journals. In the USA, Goer (2010) has noted how concerns with maternal rights in childbirth that were expressed in the 1950s persist with the current failure to provide one­ to­one care in labour, and an undermining of women’s choice in labour de cisions. Venezuela became the first coun try to legislate to outlaw obstetric viol ence, targeting the recourse to medical inter ven tions like caesar­ ean sections without prop erly informed consent (D’Gregorio 2010). Both of these elements of care should be funda mental human rights because the evid­ ence of their bene fits has been comprehensively estab lished (Hodnett et al. 2009, Kirkham 2004). Against this backdrop, waterbirth conjures up the most gentle of entrances for a new life, and in this chapter I want to ex plore its evid ence base to date for a range of labour and birth aspects. These can be divided into envir on­ mental, thera peutic, physiological, psychological and professional.