The essay describes the concept and evolution of a countersignature and prerogatives of the President of the Republic of Poland. The countersignature is a special signature (a consent) of a member of the Council of Ministers which is necessary to validate the President’s legal (official) act. Prerogatives are enumerated in a constitutional act as presidential competences, which do not require a signature of a member of the Government (a countersignature). The author claims that the institution of independent presidential competences was invented by Polish lawyers and used for the first time ever in the Polish Constitution of 1935. Further, the author describes the evolution of the institution of a countersignature and prerogatives in the Polish political system. It is said that nowadays the number of independent competences does not have such significant importance as it is claimed in constitutional law and in reality prerogatives do not strengthen the political position of the President significantly. His/her power depends on whole relations between the authorities described in constitutional provisions.