Education is a fundamental pillar of social prosperity, and the method of financing and the quality of available education have a direct impact on the development of human resources, economic and social progress, and the stability of society. The subject of this research is to investigate ways of financing primary and secondary education in selected counties of the Republic of Croatia and their mutual comparison. The paper presents a hypothesis according to which there are significant differences in the method and structure of financing of elementary and secondary education among selected counties in the Republic of Croatia. Namely, due to the decentralized financing of elementary and secondary education, local and regional authorities must look for alternative sources such as European grants. Because ot these reasons there are inequalities in the level of financing and the quality of educational infrastructure between counties. The City of Zagreb, Varaždinska county and Primorsko – goranska county, due to larger funds in the local budget, achieve better conditions in the education system compared to rural areas in the rest of the Republic of Croatia. Part of the investment in elementary and secondary education was also financed by the European Union, so Varaždinska county is the leader in terms of investment in education per inhabitant, while Primorsko – goranska county and the City of Zagreb are examples of good investment practice with the "Teaching Assistants" project provided by grants of EU for the education of students with developmental disabilities. The city of Zagreb stands out as the leading county in the Republic of Croatia that made maximum use of EU funds in the reconstruction of elementary and secondary school buildings affected by the earthquake.