The creation of European Union agencies (EAs) has gone hand in hand with some (normative and empirical) discussions about their independence, democratic legitimacy, control and accountability. In previous studies I have examined the professional trajectory of management board members of EAs identifying their career links with politicians and stakeholders, and the professional trajectories of scientific panels members with the aim of assessing EU agencies’ inclusiveness and openness inclusiveness and openness to a diversity of experts. This article takes a step forward by analysing whether the professional background of such members determines specific accountability practices/outcomes. In particular, this article aims to identify accountability mechanisms performed in two types of agencies: on the one hand, agencies characterized by having board members and experts with high levels of professional experience in public sector organizations — the case of the European Institute for Gender Equality (EIGE) — and, on the other hand, agencies in which the majority of their members have worked in the private sector — the case of the European Food Safety Authority (EFSA).