The paper focuses on a comparative analysis of the responsibility of authorities to act on equalizing regional disparities, starting from the principle of equality. In addition to regional disparities and the principleof equality, two key concepts of work (responsibility and efficiency of the authorities) are viewed in the context of the general theory of constitutional law. The starting point of the paper is the perception of regional disparities that are defined as amultiple problem in the territorial-political community. This pointsto the fact that regional disparities are the reason for public authorities to act in the direction of their equalization. The next chapter analyzes the role of the constitution in resolving regional disparities and lists several constitutional functions that encourage the uniformity of regional development. The fourth, the most comprehensive and most important chapter analyzes the constitutional responsibility of the authorities to equalize regional disparities in different countries (the Republic of Croatia, Slovenia, Northern Macedonia, Montenegro, Serbia, Italy, Spain, the Federal Republic of Germany and Switzerland). The paper is based on the following hypotheses: H1: Although cohesion policy at the EU level aims at reducingregional disparitiesthrough shared competences between Member States and the EU, some Member States also express constitutional requirements for equalizing regional disparities; H2: Constitutional basis of the government's responsibility for equalizing regional disparities exists in different countries, regardless of their governmentsystem; H3. Effectiveness of public authorities in terms of equal developmentand living conditions within a nationalterritory shows significant differences from state to state.