This study explores the place of play in KS1 classrooms and the perspectives of teachers and headteachers in adopting play-based practices at the start of primary schooling. Data were collected from a survey of KS1 teachers asking for their views of play as an integral part of KS1 pedagogy. This was followed by interviews with eleven headteachers of schools where a play-based approach is embedded. Findings revealed that whilst teachers were in favour of play in KS1, policy constraints and, in particular, the beliefs of their own headteachers, very often acted as a barrier to the implementation of play in their school. The interviews with the headteachers of schools where a play-based approach is encouraged, reveal the influences on their thinking and beliefs, which include the advocacy of their own teachers.