Pursuant to the Constitution of the Republic of Croatia, the capital city of the Republic of Croatia is Zagreb. City of Zagreb holds a special position within the administrative – territorial organization, and the City’s position, organization and scope of activities are regulated by the Act of the City of Zagreb. City of Zagreb is also the seat of Zagreb County, the Croatian Parliament, the President of the Republic of Croatia and the Government of the Republic of Croatia. The thesis also explains the special status the city has as a local selfgovernment unit (the city) which at the same time has the position of a regional selfgovernment unit (county). The thesis provides detailed description of the city administrative bodies; the City Assembly as the representative body of the citizens of the City of Zagreb and the mayor, who is vested with executive power in the City of Zagreb. The thesis also provides a detailed description of the local self-government in the City of Zagreb, which is divided into city districts and local committees. The thesis tries to find the answers to the challenges local self-government faces, such as the city administrative bodies neglecting the local selfgovernment, but the thesis also raises the question of sustainability of this type of local government, given the fact that other European cities are not familiar with this type of the local self-government system.