Bruce Ackerman’s theory of constitutional moment met numerous commentaries and analysis, recently Polish scholars have used this theorem in constitutional and political discourse, subordinating it to questioning about pre-conditions to create and enact a new constitution. This paper concerns the constitutional moment theory, to order and present basic assumptions, content and phases of the constitution-making process in Ackerman’s view. It emphasizes some prevailing features of the constitutional moment concept, sometimes omitted in current discourse. Firstly, the constitutional moment regards not only a formal change of the constitution, but also (maybe - above all) change of constitutional interpretation. Secondly, the process of the change has four stages, in which a conflict and crisis concerning constitutional norms are unavoidable. Finally, the most important part of the constitutional theory is the conclusion of the power of the Sovereign (people) which is restored during constitutional moment to express its will and make a constitution.