This paper discusses the role of modern matrons and their work in the reduction of health care acquired infections. Based on in-depth interviews with 10 matrons in a health care trust in the UK Midlands region, we explore how they construe their working lives and their view of the powers they have to enhance cleanliness and reduce infection. Despite claims in policy documents that modern matrons would have considerable authority, participants felt their control over the environment was limited, and could be accomplished only through reflecting, communicating and liaising. The lack of formal structures of accountability and personal authority meant that participants could be characterised as working in what Courpasson calls a ‘soft bureaucracy’. Moreover, in the light of limited power to command cleanliness, participants described their role in terms of reflexive work upon themselves and their interpersonal environment, involving self-scrutiny of their activity, channelling information, empowering, facilitating and remodelling the emotional environment of care delivery. This aligns with accounts of the self in the workplace from Anthony Giddens and Nikolas Rose where it is seen as a reflexive project. We explore why the project of the self seems to have eclipsed the managerial role as the major focus of matrons’ work.