This article focuses on development work led by Nikki Smith who participated in a teacher leadership support group designed especially for educators in the field of early childhood. Nikki's project improved the provision and practice of a particular type of learning environment for very young children, one that is created and packed away each day. Nikki's story is instructive in that it shows very clearly how teacher leadership is key to advancing practitioners' professionality. It demonstrates how the programme of support enabled Nikki to create and enhance professional knowledge, positively influencing her colleagues and the conditions in which they work. The article demonstrates how the teacher-led development work methodology might be adapted to mobilise early years educators' enormous leadership potential.