Poland's Constitution of 2 April 1997 is a result of fundamental transformations of Poland's political system, initiated probably in April - September 1989 and manifested in numerous legislative acts in the years 1989-1997. During these 8 years several constitutional acts were temporarily in force, Poland ratified the European Convention on the Protection of Human Rights and Fundamental Freedoms and other significant conventions, many important laws were adopted and the political practice typical of modern democracies was established. In this context, the new constitution has rather incorporated those transformations that have proved to be effective, with only slight corrections, and not departed from the practice of the preceding 8 years. Nevertheless, the Constitution of the Republic of Poland, as a comprehensive legal act, reveals its current role of an act of the highest rank in the hierarchy of legal acts. The article provides an analysis of such influence on many levels corresponding to its formal structure and, particularly, its division into chapters. Such influence usually implements constitutional principles and values, which is particularly confirmed by the content of legislation and jurisprudence of the Constitutional Tribunal and other courts. However, in the author's opinion, it has also some defects. Among such defects are, above all, the lack of independence of public prosecutors from the government administration and the practice of frequent reconstructions of the composition of the Council of Ministers performed in fact by the Prime Minister, with only formal participation of the President of the Republic and without approval from parliament. This raises doubts whether we can really speak about the functioning of the government enjoying the confidence of parliament (its lower chamber), as provided for by the Constitution.