Purpose: In light of the public resistance towards the deepening of European integration (EI) and the role that education is anticipated to have in supporting the process, this paper examines the conceptualisation of EI in lower secondary textbooks for History, Geography and Civics. Specifically, the paper asks whether EI is conceived of as a vehicle for the post-national transformation of Europe or as an instrument for interstate cooperation. Design: Drawing on the insights of EI theories and content analysis, the paper adopts a qualitative approach. Applying this approach, the textbooks currently used in Slovakia's lower secondary schools are analysed as a case study. Findings: The findings are inconclusive with regard to the research question. Indeed, while the sources are positive about EI, the findings suggest some problematic aspects in terms of how the textbooks analysed conceive the nature of the integration process. Research implications: The approach taken in this paper could be replicated on a larger scale in other countries. Practical implications: Curricula and textbook designers ought to consider how to include a critical discussion on the deepening of EI in secondary education.