This study aimed to characterize the process of knowledge recontextualization (Bernstein, 1990) based on the functions that Knowledge Genres perform in elementary school textbooks, used in Chile. The analysis was conducted on a corpus comprising the 11,139 instances of the 15 Knowledge Genres reported by Ibáñez, Moncada, Cornejo and Arriaza (2017), adopting a top-down bottom-up approach (Biber, Connor & Upton, 2007). Our results reveal 11 functions that can be performed by Knowledge Genres in school textbooks. Additionally, it was observed that some functions are realized in one or more Knowledge Genres and, also, that some Knowledge Genres perform two functions. Based on these results, it can be concluded that recontextualization can also be observed in the functions that Knowledge Genres perform in school textbooks and that such functions vary across subjects.