There is an ongoing debate over the nature and necessity of teacher "professionalism", particularly in early childhood education. In England, this sector was a particular focus of the education policies of Labour governments in the 2000s, and this had a significant impact on early childhood teachers and classrooms. This article examines the impact of a specific policy: the introduction of a statutory assessment system called the Early Years Foundation Stage Profile (EYFSP) for teachers working with children aged four to five years in primary schools in England. Data from year-long ethnographic studies of two classrooms and extensive interviews with the class teachers are used to explore the relationship between this policy and the teachers' ideas about their own professionalism and status. It is argued that the introduction of the EYFSP has had contradictory effects on teachers: it raises their status and demarcates specific early years expertise, but simultaneously requires them to provide evidence of their judgements. Furthermore, the extent of the EYFSP requirements results in teachers feeling incompetent and also engaging in practices of "cynical compliance", where they adhere only to the minimum standards. It is argued that this policy has emotional costs for teachers as it has an impact on their views of themselves as professionals. (Contains 4 notes.)