The article concerns the dilemmas of legitimising power in Poland, based both on the contemporary achievements of theoreticians and on a discussion of the realities of the political system in Poland. The analysis focuses on the assumption that, on the one hand, the legitimation of power is its recognition as legal, operating on the basis of applicable legal norms, and on the other, the recognition that a specific power has social grounds for having the rule. The legitimacy of power in Poland is based on the authoritarian experiences before 1989, the democratic transformation, and the crisis of constitutional democracy after 2015. The discussion is based on a reference to Montesquieu’s division of powers and an analysis of the legitimacy of the legislature, the executive, and the judiciary.