The evaluation of local policies is an activity at a cross-roads where operational and scientific domains meet. In conciliating these two approaches, French politico-administrative elites and researchers from the social sciences today find themselves confronted with four trends which structure this article : relative decline in the importance of corporatist references in the French central administration, a context of local politics where the greater accent is on contractualisation, where evaluation as a discipline is in the process of evolving from a relatively formalized model of action (aid for decision-makers) towards a more participative yet fragile model (the role of intermediary or «companion »), a university milieu in search of new ways of involving itself in society. This text is an attempt to go beyond a straightforward inventory by outlining several ideas as to how one might better use evaluation as a means of bringing together actors, experts and decision-makers involved in the dynamics of local politics