The professionalization of certain management occupations, such as project management and human resource management, has been neglected in recent debates on professions, which instead focus upon the deregulation of collegial professions or the failure or unwillingness of new expert occupations to professionalize. Project management represents one of a handful of ‘management professions’ which confound this interpretation, explicitly pursuing a ‘corporate professionalization’ project with some degree of success. This paper focuses on the strategic activities of the principal British professional association in this field, the Association for Project Management (APM), as it negotiates a path between exploiting established sources of legitimacy and exploring a novel conception of professionalism. In the process, the association manipulates collegial and corporate logics of professionalism, in terms of its relationships with key stakeholders, its global orientation, its knowledge base and strategies of occupational closure. Drawing on interviews with APM officials and broader documentary analysis, we analyse the conditions which have produced this hybrid model of professionalism, highlighting the pragmatic management of tensions through the combination of distinct, even contradictory, professionalization logics.