This paper investigates the dynamics of legitimacy in relation to IT based production of knowledge within a context of strategic change. Applying a resource-based view on strategy we analyse the development and use of an MIS in a local health care organization in Norway. Although the resource-based view on strategy is highly relevant in analyzing strategic use of IT in health care, it should be complemented with theories that deal with the context more specifically. We argue that due to the contradictory logics, interests and values at work in such an organizational context, the dynamics of legitimacy are of crucial importance for the construction of MIS and the possibility for using it effectively. The case analysis demonstrates that through the process of MIS development its structure and functionality reflects the interests and values legitimately at work in the field. However, the analysis also demonstrates that the MIS is biased towards an administrative logic, which indicates that the extensions of the system and the compromises made are only partial. The paper concludes that strategic use of IT within such a context should face the problem of politics, but this is highly problematic because of the apparently apolitical nature of new public management reforms.