European administrative networks (EANs) are a key building block of the European Administrative Space (EAS). Crucially, they are to fill the gap between the EU's policy ambitions and its limited administrative capacities. Whereas ample research has been done on policy preparation networks, the role of implementing EANs has received less attention in the EAS literature. This article fills this gap by providing a systematic review of relevant insights in four adjacent literatures: EU governance; international relations; public administration; and EU compliance. Employing a systematic literature review, it reports divergent findings on EAN establishment, functioning and impact, as well as variant normative evaluations. These variant findings partly relate to a lack of comparative research, selective policy coverage and predominant focus on North-western states. We conclude by suggesting a number of lines for future research on these four important themes, arguing that the crucial question will be which impact these EANs have on the national implementation and enforcement of EU law.