The article analyzes the establishment and development of the legal regulation of administrative proceedings in the Republic of Poland. It is noted that the organization and activity of administrative proceedings in the restored Republic of Poland was based on two models: the previous Austrian administrative proceedings and the Prussian administrative proceedings. As a result, the formation of the Supreme Administrative Tribunal was foreseen in the Republic of Poland, which testifies to the significant influence of Western European traditions. The legal basis for its creation and activity was the law of August 3, 1922, the powers of which were specified by the regulations of the Supreme Administrative Tribunal.
 The competence of the Supreme Administrative Tribunal included the decision on the legality of decisions and orders in the sphere of governmental and self-governing administration. It was established that the restored Polish state, from the first days of its existence, began activities aimed at forming borders, state authorities, the army, law enforcement agencies, including the judiciary, namely the creation of an effective Polish judicial system and judiciary. It is described that the formation and development of the judicial system of the Second Polish-Lithuanian Commonwealth was a long process and included two stages, which can be divided into two stages using the characteristics of the functioning of various systems of judicial bodies, their adaptation to new socio-political conditions and the growth of deformations caused by the violation of democratic principles of the March Constitution of 1921 and the creation of a unified system of general courts and its reformation in the direction of anti-democratic principles.
 It has been established that the foundations of the judicial system in Poland are the Constitution of 1921, which recognized the courts as a separate branch of government, independent of the executive and legislative powers, which in practice was not always implemented. It is noted that a feature of the judicial system of the Republic of Poland was the introduction of administrative proceedings, the formation of which took place immediately after the restoration of the Polish state. Attention was drawn to the fact that after the Second World War until 1980 there was no separate administrative court in the Republic of Poland. Administrative justice was revived in Poland on September 1, 1980, when the High Administrative Court, established under the law of January 31, 1980, began to operate.