Teacher professionalism in England may be considered to have been shaped by the set of professional standards, and the accompanying statutory performance management system, introduced by the Labour government in 2007. More recently the coalition government's 2010 White Paper, "The Importance of Teaching", announced reforms that will potentially re-shape teacher professionalism. In this article I examine the "shape" of teacher professionalism in England, as defined by the professional standards. I reveal it to be a lop-sided shape, indicating a professionalism that focuses predominantly on teachers' behaviour, rather than on their attitudes and their intellectuality. Presenting my conceptual analysis of professionalism, and examination of its link with professional development, I consider whether--and to what extent--teacher professionalism may in fact be shaped by government-imposed reform. I conclude that "enacted" professionalism may be quite different from "demanded" professionalism, and shaping professionalism involves a complex and indecipherable process that is better understood by examining the process whereby individuals develop professionally. (Contains 1 table and 2 figures.)