The subject of research presented in the article is the system of government in Poland. The considerations concern the relationship between the normative solutions defined in the Constitution of the Republic of Poland of 1997 and the influence of the EU on the modification of political solutions in Poland. It was hypothesized that after Poland’s accession to the EU, the system of government in Poland changed in terms of political practice. It has been shown that functioning in the EU resulted in a departure from the characteristic rationalization of the system of government and brought it closer to the parliamentary model. The research was based on the following methods: institutional-law, systemic and comparative.