Over the last fifteen years, a significant reform of the secondary school mathematics curriculum in Ireland took place. A major aim of the reform was to move away from instrumental learning and to develop mathematical proficiency and problem-solving skills in line with international trends. In this article, we study textbook tasks from popular textbook series in use before and after the reform. Our purpose is to use the Task Analysis Guide to investigate the level of cognitive demand of the tasks, and the opportunities they offer students and teachers to achieve the aims of the curriculum reform. Our analysis shows that the vast majority of the 7635 tasks studied have a low level of cognitive demand; consequently, they mainly offer students opportunities to develop procedural fluency. We note that the post-reform textbooks do contain more tasks with high levels of cognitive demand than their pre-reform counterparts, however the increases are small. This study will be of relevance to countries where textbooks are not designed or approved by curriculum developers.