One of the main issues connected with terrorism – a “crime without borders”, a complex phenomenon the definition of which has proven elusive, is terrorism financing and money laundering. The Polish legislator – in the Polish Banking Law – imposes on banks (within the scope of their legal definition) a duty of counteracting money laundering and terrorism financing, which corresponds with the significant role of banks and other financial institutions when it comes to the prevention of terrorist crimes. On the basis of the Act on Counteracting Money Laundering and Terrorism Financing, a special system was created – the aim of the regulations is to facilitate successful performance by banks of their duties. In the Act, the office of the General Inspector of Financial Information was created, with an important task of controlling the realization of banks’ duties, as well as cooperation with relevant services and improvement of international antiterrorist activity. Beyond any doubt, the functioning of the Polish system could be guaranteed by broader legal and institutional frameworks on an international level, the achievement of which is contingent upon the activity of the European Union and the United Nations. A significant element in the fight against terrorism financing crimes is also proper training of the banking sector employees and officers, as well as ensuring proper communication and cooperation between them.