The paper presents the results of a research conducted with the aim of determining the contribution of Science and Social Studies textbooks in the formation and strengthening of the national identity of younger students in primary school. The theoretical part of the paper provides an overview of different conceptualizations of the concept of national identity, as well as an overview of the research on the role of program frameworks and educational content in the development of the national identity of children and young generation. In accordance with different conceptualizations, national identity has been operationalized in 11 categories: religion, customs and traditions, national feelings, language, symbols and insignia, solidarity and togetherness, cultural heritage, important personalities, geographical concepts, family, and general information. The method of theoretical analysis and the method of content analysis were applied in the research. The units of analysis are the sentences of the basic text of the textbook. The research included the Science and Social Studies textbooks in the lower grades of primary school (N = 12). The results of the research indicate that textbooks insufficiently contribute to the formation and strengthening of the national identity of the younger school-age students, in terms of all considered categories of national identity. The conducted analysis implies that it is possible and desirable to strengthen the contents of national significance and, to a greater or lesser extent, incorporate them in all thematic units, which would significantly increase the overall share of the contents on national identity.