Abstract
For more than ten years, the development of management control practices inpublic sector gave rise to many researches which some, focus on role that accountants play.The aim of this paper is to understand the determinants of management accountants' legitimacy in professional bureaucracies and to define how individuals, who embody this function, had survived in this unfriendly environment. From a case study at the French Atomic Energy Commission, we highlight four profiles of management accountants: the young novice, the new convert, the chameleon and the king's advisor.The results show that the legitimacy of the controllers should not be studied through his generic definition. Instead, it must be considered as a polymorphic judgment based on manifold determinants. It also allows to replace the individual at the center of the study field of the new managerial practices in public organizations.