The goal of this work is to master the theoretical and practical knowledge in the field of public procurement in modern market conditions. An important part of this work, or the most important step in the research, is the data collection. For this purpose the data from the professional literature that it covers will be collected and presented from the field of public procurement in a way that will be recounted, quoted or theoretically assumed. The public procurement procedure should only begin when the planned procurement is in place, which is also the most important step for the implementation of the public procurement procedure. The contracting authorities are obliged to respect the principles of public procurement in relation to all economic regulations, which is the principle of free movement of goods, the freedom of establishment, the freedom to provide services, the principle of competition, the principle of equal treatment, the principle of prohibiting discrimination, the principal of mutual recognition, the principle of proportionality, and the principle of transparency. Public procurement is an important part of every modern economy, and an effective public procurement system is needed to achieve the objectives of the free market and to ensure the conditions of competition. Public procurement is a procedure that precedes the conclusion of a contract. In the study of this subject and the writing of this work, available literature and internet sources were consulted.