This article presents an analysis of how legislators on international, European and national level combat the financing of terrorism. The central question in this article is whether European regulations concerning the prevention of money laundering and the financing of terrorism, are effective, proportional and mutually harmonious. Now that many regulations in this field have been established by intra-national bodies, it is important to examine how these regulations are further elaborated in the respective national systems. This article gives a broad overview of legislative initiatives of the UN, USA, FATF, EU and Council of Europe. The Netherlands for numerous reasons serves as a legal example. It is concluded that measures taken or proposed to avoid or at least reduce the financing of terrorism are quite effective to prevent abuse of the financial system. On the other hand, these measures increase the risk of underground or illegal financing, which is even more difficult to control.