Public procurement is the most important instrument of the public sector through which investment projects are implemented, especially in electricity infrastructure facilities. The electricity sector is an extremely important sector in business because it enables electricity to always be available to all consumers in the required quantities and of adequate quality. Electricity as a driver has entered almost every area of human life and which is why its demand has become extremely high. Public procurement carried out by public electricity entities has a direct impact on financial developments in the country because this area regulates the presence of public finances on the market. The EU and Croatian institutions have developed legal regulations in the field of public procurement in order to develop the system in a positive way with the aim of new investments and entrepreneurial activity. The public procurement system is significantly influenced by legal regulations as well as the judicial system that controls procedures. Given the large impacts of public procurement, mostly on the market of goods, works and services, but also on the whole society, a survey was conducted on the economic impacts of public procurement in the public electricity sector of the Republic of Croatia. Documents published in the public procurement system as well as the experiences of experts were used for the research. The aim of the research was to determine the correlations between the implementation of public procurement procedures in the public electricity sector regulated in accordance with EU and Croatian legislation and the quality (reliability) of the public electricity system, to investigate the model of selection criteria, the impact of qualitative selection criteria on product quality, works and services and the overall relationship to some economic indicators in the economy as a result of the impact of the public procurement system. The analysis of data collected during the research concluded that transparent and efficient implementation of public procurement is key to investing in infrastructure projects, which affects GDP trends, small and medium enterprises, liquidity and etc. The public procurement system significantly affects the general liquidity of the economy, and shortening payment deadlines allows for a higher rate of capital turnover. Investments in the electricity sector enable security of supply to consumers, reliability of the electricity system, better quality of electricity and lower electricity prices.