While EU interest group politics has gained substantial academic attention in the last decades, the interactions between organized interests and EU regulatory agencies is still relatively understudied. Nonetheless, the theoretical and empirical research on the delegation to and functioning of regulatory agencies has developed various, sometimes conflicting, views on stakeholder involvement in regulatory policymaking. This papers analyzes, by means of a meta-analysis, how scholarship on regulatory agencies understands interactions between societal stakeholders and regulatory agencies. More specifically, I will demonstrate a considerable conceptual bifurcation within this literature. On the one hand, many European scholars argue that involving interest groups in agency decision-making enhances the legitimacy of regulatory policymaking as these groups contribute to the ‘democratization of expertise’. American inspired literature, in contrast, points at the danger of ‘agency capture’, rendering agencies vulnerable to acting in accordance with special interests rather than the general public interest.