This article presents the functioning of the European Union Rule of Law Mission in Kosovo (EULEX Kosovo) as the largest and most expensive civilian crisis management mission deployed to date by the European Union (EU) in the context of its Common Security and Defence Policy (CSDP) as part of the Common Foreign and Security Policy (CFSP), which represents one of its fast-developing policy areas. The present study covers the stages of the planning, deployment and functioning on the ground of EULEX by illustrating its performance in the main rule of law areas through abundant empirical data and evidence. Despite the difficulties encountered by the EU in emerging as a fully-fledged global foreign and security actor, the problem-solving culture developed by Brussels-based CFSP and CSDP bodies has facilitated the formulation and implementation of an active EU foreign policy towards the Western Balkans, including Kosovo. EULEX has been deployed in this context of EU’s structural foreign policy by also complying with its self-image as a ‘civilian’ and ‘normative’ power. The main argument of this article is that while EULEX has greatly contributed to the preservation of security and stability in Kosovo, its role in the Europeanisation of the Kosovo national political system has been rather limited. The lack of a strong and unambiguous political will by the Kosovar political class has been the main reason for the limited impact of EULEX in establishing local rule of law institutions able and committed towards an effective fight against organised crime and corruption. The experience of EULEX demonstrates that an effective rule of law cannot be established by an international mission, but only by local institutions under strict EU conditionality.