Contracts for public procurement play a key role in the expenditure of public funds and have a significant impact on the economy, while ensuring transparency and legal certainty. Public procurement procedures are regulated by legislation and focus on the fair distribution of resources, whereas the legal nature of these contracts remains a matter of debate. Although some theorists consider these contracts to be purely civil law in nature, their administrative law character arises from the fact that contracting authorities are often public bodies acting in the public interest. In Croatia, the State Commission for the Supervision of Public Procurement Procedures plays a key role in ensuring the legality of procedures. The decisions of the Commission are not subject to appeal but can be challenged by an administrative dispute before the Administrative Court, ensuring speed and continuity in contract conclusion. However, the public procurement system is often hindered by frequent legislative changes, creating uncertainty for participants. Despite EU directives providing flexibility, Member States define the legal nature of contracts themselves, which can lead to legal uncertainties. The aim of this paper is to analyze the legal nature of public procurement contracts and confirm their administrative law character. The paper also highlights the importance of a stable legal framework for the efficient and transparent implementation of public procurement, which has far-reaching consequences for the economy and the public sector.