Direct decision-making in the Republic of Croatia is guaranteed by the Constitution of the Republic of Croatia, which recognizes the role of the people as sovereign, and provides for the right to express the will of citizens through a referendum. The Law on Referendum and Other Forms of Personal Participation in the Exercise of State Power and Local and Regional Self-Government regulates the calling and implementation of referendums and other forms of participation of Croatian citizens with voting rights in the exercise of state power and local and regional self-government. The area of local referendum is to a certain extent regulated by the provisions of the Law on Local and Regional Self-Government. In the context of the topic of the paper, the Constitutional Law on the Constitutional Court of the Republic of Croatia is also important as one of the constitutional sources that regulates the conduct of referendums in Croatia. In Croatia, therefore, a referendum is an expression of democratic decision-making and the main means of direct democracy, ie a form of direct decision-making by voters in the exercise of state power. Voters have the right to decide on issues determined by the Constitution of the Republic of Croatia and on issues within the self-governing scope of local and regional self-government units determined by law and the statute. In Croatia, a referendum can be state or local, and other forms of citizen participation and decision-making are: advisory referendum, citizens 'assemblies and citizens' petitions. Croatian citizens have the right to participate in the state referendum, and voters who reside in the area of the local self-government unit, ie theregional self-government for which the referendum was called, have the right to participate in the local referendum. In the referendum, voters decide directly by secret ballot. Deciding on the referendum is carried out by the majority of voters who voted. The State Referendum Commission and the Constitutional Court of the Republic of Croatia monitor the constitutionality and legality of the state / local referendum.