This paper explores how current 'patient safety' reforms offer to change the regulation of medicine. Drawing on existing literature, it is argued that this policy agenda represents a new frontier in medical/managerial relations, introducing a disciplinary expertise within the health service that provides managers with the knowledge and legitimacy to survey and scrutinise medical performance, made real through procedures for incident reporting and root-cause analysis. The extent of regulatory change is investigated, drawing on an ethnographic case study of one hospital. It is shown that, as with other organisational and managerial reforms, doctors are resisting managerial prerogatives through seeking to subvert and 'capture' components of reform. I describe this as 'adaptive regulation' to account for how doctors seek to maintain their regulatory monopoly and limit managerial encroachment. It is speculated, however, that this process could signal the future 'modernisation' of medical professionalism where emerging managerial discourses, within the wider context of public sector reform, are increasingly internalised with medical practice and culture. This leads to new and rearticulated forms of self-surveillance, self-management or 'governmentality', ultimately negating the need for external groups to explicitly manage or regulate professional practice.