The Treaty of Lisbon has provided new opportunities for national parliaments to become more active in EU affairs and to take up a greater role in European decision-making. At the same time, bicameral systems are increasingly challenged: in many member states the added value of upper chambers is questioned. However, some scholars have described how the involvement in EU affairs can provide upper chambers with a renewed raison d’être. In this chapter, the practice of bicameral parliaments with regard to the scrutiny of EU document is examined. All 13 bicameral systems in the EU are part of the analysis. The central questions are whether the two chambers have a similar approach in scrutinising EU documents and to what extent a cooperation between the two exists. The findings show that involvement in EU affairs provides opportunities for upper chambers to punch above their weight, as the EU’s institutional provisions can impact existing power relations and intra-parliamentary cooperation.