For more than a decade now, evaluation has developed considerably in France, thanks in particular to the Société Française de l’Évaluation, whose charter sets out a number of principles designed to guide the work of evaluators. This article examines how the evaluation process surrounding a regional public health plan (referred to as PRSP) – itself being a new instrument for regional planning in France – accords with one of these principles, which specifies that evaluation must be framed according to “a three-fold logic involving public management, democracy and scientific debate.” Our analysis shows that while this evaluation was driven primarily by managerial concerns (i.e., assessing the capacity of the plan to structure health policy in a region), it also provided an Opportunity for restoring dialogue with a range of actors by opening up a space of cooperation and consultation. In addition, in order to ensure the legitimacy of the evaluation's conclusions, the knowledge produced by the evaluators had to rest on an irreproachable methodology. This example illustrates how evaluation, in the French tradition, is a process that strives to reconcile the viewpoints and expectations of managers, scientists and the general public; it is also a process that brings out lines of tension and areas of complementariness between these three logics.