By means of library media programs (LMPs), primary school librarians are at the forefront of educating young library users and teaching them the skills necessary for the independent location and acquisition of bibliographic materials and information. In teaching young library users about the independent use of non-fiction works, a professional and transparent shelving system and well prepared and implemented LMP (2005) lessons play an essential role. Because the majority of research studies into Slovenian library services focus on fiction and library departments with children%s and young adult literature, my master's thesis focuses on the shelving of non-fiction collections in primary school libraries. Closely studied during workplace training at the Vito Kraigher Primary School library was the non-fiction shelving system that was presented to sixth graders in an LMP lesson. Because the LMP program (2005) indicates familiarization with the universal decimal classification (UDC) system and the gradual introduction of pupils to locating bibliographic sources according to UDC classifiers, the base objective of my master's thesis was to determine to what extent LMP lessons covering the non-fiction shelving system can enhance a pupil's ability to find them. Methods/approach: The study made use of a questionnaire and the observation method. Tested by means of a questionnaire in the form of a work sheet adapted for sixth grade pupils were the knowledge on the location of non-fiction books in the school library, the knowledge on the classification of certain non-fiction books according to the adapted UDC system and satisfaction with it, and the problems faced by pupils in locating non-fiction literature. The ability to independently locate and utilize non-fiction literature covering a predefined topic was studied using the observation method. Also observed was the pupils' ability to get around the non-fiction collection at the school library, the time required by pupils to find the sought piece of non-fiction, and the amount of explaining needed or the content of questions posed by the pupils to the librarian during their locating of the sought piece of literature. To determine how effective LMP lessons about non-fiction shelving and the UDC system are with sixth graders, the study at Vito Kraigher Primary School was conducted in two phases. The first phase included pupils of grade 6A and was conducted on 9 June 2017, following the implementation of the lesson; and the second phase including pupils of grade 6B was conducted on 22 May 2017, before the lesson and without any preliminary explanation on the nonfiction shelving system. Results: Pupils of both grades were fairly successful in locating non-fiction materials literature in the school library. There were some notable differences in terms of getting around the school library and non-fiction collection, and in the time required to find the literature covering the predefined topic. The majority of grade 6A pupils found the required non-fiction faster than their peers from grade 6B. Additionally, the contents of the literature found by the pupils were more related to the predefined topic, they found more literature, and were more confident in searching for the library materials. Study limitations: Analyzing the results, it has to be noted that the questionnaire and observation method which were used to gather the data have certain drawbacks. In addition, the study sample was too small and not representative enough to draw generalized conclusions for the entire population. Therefore, it can only be assumed that the acquired results reflect the significance of LMP lessons on the shelving system and the locating of non-fiction in school libraries in general. Originality/usability of the study: For the purpose of the study, a lesson was conducted to aid and inspire librarians in teaching about non-fiction shelving and setting up the UDC system.