This article fills a gap in the literature on the European Neighbourhood Policy (ENP) by examining the role that epistemic communities play in the policy. It follows an interdisciplinary approach for categorising their role in the ENP and the use of their knowledge by policymakers. Based on the examination of two key areas of the ENP, anti-corruption and rural development, the study challenges one-dimensional assumptions, which claim that expertise and knowledge improve the technicaleconomic efficiency of EU policies. The findings of this research suggest that the knowledge of epistemic communities takes three different forms for policymakers: political/symbolic, instrumental and conceptual.