This thesis employs a case study approach to examine the educational theories and practices of early childhood teachers in New Zealand. The traditional conception of education as an 'applied science' is rejected in favour of a praxis account in which educational theory consists of the more or less consciously held beliefs, values and assumptions of practitioners as manifested in their practice. It is argued that theory and practice are mutually constitutive and dialectically related parts of a whole. However a review of the literature on early childhood teachers' beliefs reveals that educational theory has been largely conceptualised as a body of knowledge which teachers apply to their practice. Following 80 hours of observation in two early childhood centres which focused on six teachers interactions with eight 4 year old children, interviews were conducted with teachers and children to explore their views of practice. Six case studies are presented in which the beliefs and practices of these early childhood teachers are examined and the nature of their 'operational theories' explored. In the main, teachers identified the psycho-social domain as their primary focus, with only two teachers making reference to cognitive development. Teachers described children as 'learning through activity' and most subscribed to a non-interventionist view of teacher role. However all teachers were found to explicitly teach socially appropriate behaviour, this being the focus of the majority of interactions. Teachers offered apparently contradictory accounts of play. It is argued that these reflected both their formal and intuitive knowledge and that it was the latter which informed their interaction with children. Teachers' abilities to theorise their practice differed. While some offered full and relatively coherent accounts of the beliefs which informed their practice, most teachers 'operational theories' contained 'gaps' and apparent inconsistencies. While the problems associated with making peoples' beliefs explicit are acknowledged, it is also argued that early childhood education will be most effective when teachers transform their practice into praxis through critical reflection and attempts to resolve any such inconsistencies. The implications of this claim for teacher education are discussed and an interactive 'problem centred' approach proposed.