This work is dealing with the collection development policy and development of library collections for young people in the public libraries of Krapina-Zagorje County, with the emphasis on book collection. Young people are presented as a specific user group that should be offered various, contemporary and interesting content in order to retain them as library users. Therefore, the work will investigate the development of library collection intended for young people and also the development policy that a library has when selecting its collection. A two-phase research will be conducted. First part of the research explores the ways in which public libraries of Krapina-Zagorje County develop their collections for the young; then it explores their collection development policy and also finds out which book genres are mostly represented in the collections. The second part of the research is dedicated to young people as library users, and its goal is to determine their reading interests, that is, which book genres suit them best. It also investigates to which extent the collection development policy of libraries in Krapina-Zagorje County is up to date with the wishes and needs of their young users. Finally, there is also the topic of taboo motifs in literary works for the young and the question of their appropriateness. The paper will present through few examples the censorship of unwanted content in books for young people during the 20th century. It will also explore whether there are some controversial topics which are not represented in the library collections for the young today and explore the attitude of Krapina-Zagorje County libraries and their collection development policies towards such topics.