This article deals with the "troubled history" of head teachers' evaluation in Italy, as a specific strand of the controversial and fuzzy embedding of New Public Management (NPM) discourse in the Italian education system. Since the 1990s, NPM has shaped both policy agendas and professionals' subjectivities, leading the way to a process of reculturing and restructuring of education. Drawing on policy texts' analysis and in-depth interviews with key policy actors and professionals, we focus on the discursive problematisations underpinning the repeated attempts to evaluate heads and their "leadership as a lever for improvement" and their implications in terms of processes of subjectivation. The article offers a descriptive mapping of the entering of NPM in the Italian education system and analyses some ironies of the Italian NPM turn, addressing the paradoxical performative powers of the NPM strategies for the transformation of expertise and the regulation of the activities of professionals.