This article examines legal, institutional and knowledge-based aspects of counterterrorism policies developed by the European Union in the aftermath of the terrorist attacks on the United States in 2001. It focuses on selected areas in which progress has been made in the framing of the EU’s strategies, policies and actions. The following case studies are included: counter-terrorist legislation, especially the framework decision and directive on combating terrorism; the EU Counter-Terrorism Coordinator as an institutional intermediary within the EU’s institutional architecture and in the external dimension of counter-terrorism cooperation; Europol’s TE-SAT report as an instrument of strategic awareness-building, which has facilitated the explaining of the nature of terrorist threats across the EU. The main assumption underpinning this paper is that the EU has managed to ensure an uneven yet constant development of counter-terrorism measures which have contributed to a more effective fight against terrorism.