In the Netherlands, the quality of the reading curriculum is currently under debate because of disappointing results on national and international assessments of students’ reading skills and motivation. In a mixed-method study, we analyzed the content of Dutch textbooks for reading comprehension instruction (i.e., the implemented curriculum) and teachers’ evaluation and use of these books (i.e., the enacted curriculum). A materials analysis of reading comprehension lessons (N = 80) in eight textbooks for grades 4 and 5 was complemented with semi-structured teacher interviews (N = 29) and lesson observations (N = 11), with a focus on the quality of reading strategy and text structure instruction in the curriculum. Main findings are (1) a lack of alignment between lesson goals, theory, and assignments, (2) a strong focus on practicing strategies, (3) limited declarative knowledge about strategies and text structure, (4) little opportunities for self-regulated strategy application. The teachers that were interviewed mention similar problems, but still hardly deviate from the textbook’s content and pedagogical guidelines. We make recommendations to improve the quality of the curriculum.