The lack of transparency in European Union (EU) decision-making and integration has been a long-standing concern in academic and public debate. Perhaps paradoxically, parliamentary oversight of executive power in the EU is also increasingly taking place behind closed doors. This closed oversight results from internal rule-making and interinstitutional agreements established by the European Parliament and executive actors without a public debate and is primarily aimed at safeguarding EU official secrets. This paper examines the role of the European Parliament in oversight in the context of EU executive secrecy. The paper argues that, although the European Parliament asserts its prerogatives for gaining access to EU official secrets, its current practice of closed oversight does not facilitate public deliberation. The European Parliament is yet to make serious efforts to develop its public deliberation function and, in doing so, to also bring attention to possible extensive secrecy practices.