Integrated science-and-literacy programs have proven to positively affect both language proficiency and science knowledge. Because making connections is important in both text comprehension and understanding the disciplinary core ideas taught in science, it seems worthwhile to explore the potential of integrating text structure instruction in science education. Therefore, we conducted a design-based research (DBR) in collaboration with teachers in the upper levels of primary education in the Netherlands. A set of four design principles directed both the design process and the analysis of this process. Research questions were aimed at the viability of these principles and at gaining knowledge about the application of DBR within the field of an integrated science curriculum. The study demonstrates the potential of DBR as a vehicle for translating research outcomes into educational practice. The four design principles eventually resulted in materials that worked well in grades 4-6. Still, since several design principles were new to the teachers, the design task was a challenge to the teachers and required support by the researchers. Especially the selection of suitable texts proved difficult. The study yields insights and recommendations for future DBR studies in the field of science-and-literacy integrated education. Given the abundance of cross-cutting concepts that can be tied to specific text structures, there is ample room for the development of integrated materials.