The extent to which democracy functions successfully in the European Union is a hotly debated issue. Some citizens feel that EU democracy functions well as it is, whereas others perceive a democratic deficit. Which factors contribute to this variation in opinion? In this paper, we focus on the effect that the quality of national institutions has on citizens' perceptions of the democratic performance of the EU. From voter survey data from 21 EU member states (N ¼ 32410), we find that better quality national institutions correlate to lower rates of satisfaction with the EU's democratic performance. In addition, this effect is stronger amongst citizens who are more knowledgeable about national politics. We conclude by discussing the implications of our findings for our research field in particular and for society in general.