The aim of this graduate thesis is to present services and programs for children in Zagreb city Libraries on the example of the Novi Zagreb library network. The first part of the paper is theoretical and it provides a basic definition of public libraries as well as its main tasks and goals. This is followed by a brief overview of the historical development of the Zagreb City Libraries and an individual description of each type of children's department of the library, depending on the age of its users. The next chapter seeks to highlight the importance of the role of children's librarians of public libraries and their mediation between children and diverse library content. The following is a chapter on highlighting the benefits that children's users have from the active use of library services. At the very end of the theoretical part of the paper examples of good practice in children's departments in the Croatian and European context are presented. The research conducted for the purpose of writing the paper includes all six libraries in the network of the Novi Zagreb library and the questionnaire was completed by children´s librarians of children's departments of the mentioned libraries. The main goal of the conducted research is to point out the need to organize quality and diverse content and services in children's departments of public libraries for the purpose of lifelong education of children and young people and developing their love for books, reading and library as an