The subject of the thesis is focused on the legal structure of sports associations in the Republic of Croatia, ie their internal organization, the role they take in the sports system of the Republic of Croatia from the legal aspect, as well as a review of different types of sports associations with regard to size, complexity and impact on the entire sports system of the Republic of Croatia. The goals of the thesis are: to process the internal structure of sports associations according to the Law on Sports and the Law on Associations, to explain their financing, registration proces and their termination. Also, show how different sports associations operate in the sports system in the Republic of Croatia. The thesis is divided into a total of four chapters. The introductory chapter analyzes the subject, objectives, methodology and content of the thesis. In the second chapter, the author analyzes sports associations in the broadest sense and describes various sports associations given their importance for the entire sports system of the Republic of Croatia. The third chapter elaborates on the activities that sports associations deal with, describes the entry in the register and the content and importance of the statute, but also problematizes the notion of assets of sports associations as well as their financing. The fourth chapter deals with the internal organization of sports associations, and in particular their members, the assembly as the highest body of the sports association, the representation of the association in legal transport, and its termination and deletion from the register of associations. At the end of the paper, concluding remarks are made and a list of relevant literature used in writing the thesis is given.