Textbooks are a basic tool for teaching and learning reading, but also for acquiring knowledge in other subjects. In this chapter, texts used in mother tongue textbooks in the Dinaric region are compared with texts used in the IEA Progress in International Reading Literacy Study (PIRLS) 2021 assessment through the representation and length of literary and informational passages in both contexts. As one of the mechanisms in the curricular process, it is postulated that mother tongue texts can be leveraged to prepare students to deal with PIRLS texts. Our study reveals large variation in the proportions of text types used, their length, and the sheer number of texts represented in the selected mother tongue textbooks, both within and across education systems. Data show a significantly lower representation of informational texts, compared to literary texts, in all studied mother tongue textbooks and shorter average lengths compared to the length of PIRLS texts. Stakeholders who are responsible for textbook content should think of providing a greater representation of informational texts in their selection of mother tongue textbooks. This is the simplest and most reliable way to bring opportunities for informational reading closer to students. Furthermore, schools and teachers may also have the freedom to choose a textbook, so they can also make a difference and should be made aware of their responsibility and choices.