The article is focused on the effect of the establishment and application the European Union law in Poland immediately after 2004. By becoming the law binding in Poland (and other member states of the EU), the EU law effected significant changes in the sphere of law creation and application. Traditionally, in the national legal order, the law of the highest force is the constitution, while in accordance with the EU legal order, the regulations of the European law are superior in their application in the territory of the member states, including the regulations of the constitution. The present analysis explains how the dilemma of the simultaneous superiority of the regulations of the constitution and the regulations of the EU law was solved in Poland and what importance is attributed to the concept of favourable interpretation of the national law and the EU law. The present paper poses the hypothesis that the model of reconciling the regulations of the Polish law and the regulations of the European law developed in Poland immediately after 2004 was correctly established. It contributes well to Poland meeting international obligations, at the same time respecting the superior position of the constitution.