Legislative oversight of executive decisions to deploy (particularly) troops abroad is seen as a key agent of democratic legitimacy. However, parliamentary scrutiny of ESDP is at present deficient. The combination of supranational and intergovernmental elements that comprise the EU make for an ill-defined role for the European Parliament and its national equivalents in the realm of security and defence policy. This study primarily explores current practices in the parliaments of EU member states for scrutinising ESDP decision-making. Oversight practices were investigated in four case studies of ESDP missions. The results of this research highlight the wide variation in the practice of ESDP oversight across EU national parliaments. This lack of uniformity has negative consequences for the effectiveness of Europes parliamentary oversight architecture. Four models of national parliamentary oversight of ESDP were identified from the research and 25 parliamentary best practices at the national level were collated. As a result of these findings at the national level, 17 recommendations are put forward on how to strengthen the European Parliaments role in filling the present void in ESDP parliamentary scrutiny. We suggest that a number of steps may be taken to reinforce the EPs role, largely on the basis of improvements in customary practice.