Abstract While health promotion is widely acknowledged as a practice field where multidisciplinary teamwork is important, within nursing's discipline-specific literature, a strong argument can be discerned regarding the profession's belief that it has a clear and unique role to play in that field. Yet rarely is this unique role, how it arises, and specifically how its effects are to be demarcated, attended to within the discipline-specific literature. Two philosophical perspectives on science are presented and we demonstrate the extent to which these two perspectives influence nursing scholarship, including nursing practice within the field of health promotion. We then go on to argue that, for nurses to sustain their claim to a unique and important contribution within health promotion, clear articulation of the philosophical premises underpinning practice methodologies is warranted. Specifically we argue the importance of such clarity within the context of an analysis of the discourse of multidisciplinary practice as a strategy for avoiding confronting the ways in which bio-medical authority has already significantly demarcated how health promotion practice can proceed.