The article covers key legal solutions that may be used to protect classified information. It presents the legal background of these solutions, with particular attention given to the mechanisms provided for in the Act on the Protection of Classified Information of 5 August 2010. These include a new definition of classified information and restriction on the possibility to use the a ‘top secret’ clause. The key priorities of the authorities responsible for the protection of classified information were also discussed, with special focus on the Internal Security Agency (ABW). The legal regulations presented are consistent with those binding in the NATO states and EU member states, and as the validity period of the act is longer than one year, the regulations in question do not require any future amendments.