The relationship between international law and domestic law has for many years been ordered on the basis of two opposing constructs: the dualistic and the monistic. The former, in fact, required the political consent of the State to perform an international obligation, while the latter wished to eliminate this will altogether. Today, the idea has emerged to reject the hierarchical approach and to place an unequivocal emphasis on the primacy – at least when fundamental contradictions between international and domestic law arise – of national constitutions. Constitutional tribunals are to be the body to control these conflicts and to block the possible effects of international commitments in conflict with the constitution. Such conceptual changes are perfectly suited to the construction of the Polish Constitution and the constitutional position of the Polish Constitutional Tribunal. The activity of the Constitutional Tribunal in this area will strengthen the legitimacy of international law and mitigate the potential rejection of an international obligation. After all, it is one thing to reject an obligation for political reasons, and another to refuse to implement it justified by the Constitutional Court's finding of the unconstitutionality of an international norm.