This paper explores the changing patterns of professional power and the struggle for control between doctors and managers in the UK NHS, by examining the role of clinical directors. Located at the nexus of managerial and professional power, clinical directors represent and embody the challenges to medicine through increased managerialism and the profession's response to it. An analysis of the role of clinical directors reveals the changes in power and jurisdiction that have been created through clinical management. A medical model of professional power illustrates how structural and ideological changes threaten medical dominance. However, clinical directors respond to the changes by creating new forms of expertise through managerial assimilation, to extend their jurisdiction and domain within the organization and in the market. This re-professionalization, rather than de-professionalization, by doctors raises questions about the shifting power balance between doctors and managers in the NHS and between doctors within the medical profession.