A thesis submitted to the University of Luton in partial fulfilment of the requirements for the degree of Master of PhilosophyThe following thesis presents an analysis of power and control in the English National Health Service. Notably, it focuses upon power and control over knowledge; over defining what is 'valid' knowledge; over the production of that valid knowledge; and over how, what, when and where that knowledge is used in everyday clinical practice. The issue reaches to the heart of professional conception and definition and hence, control over professions themselves. The thesis attempts to demonstrate the relationship between the different professional groups in the NHS, through the analysis of national, regional and local documents, and interviews with managers, doctors, nurses, dietitians and physiotherapists in three case studies, the thesis shows the complex pattern of relations and behaviour at play. Particular attention is paid to Michael Power's notion of audit and the 'Audit Explosion', which provides a framework for the thesis, and to the work of Michel Foucault, especially his ideas about power, control and panopticism. These are used as a useful metaphor to understand and explain NBS research and audit in relation to the NHS professions. The thesis ends with a cross-case analysis which draws together the rich variety of data and concludes with an analysis of the wider sociological implications ofthe thesis