Curriculum materials' developers typically assume the existence of certain general social-educational classroom practices and norms. Conversely, the current study addresses the effects of context on curriculum enactment, focusing on the interrelations between teacher, class and curriculum materials. Each of the two case studies presented herein focuses on a teacher who taught the same subject matter, using the same curriculum materials, in two different schools. Enactment differences between teachers and between classes of the same teacher are revealed, linked with both the teacher's perception of the curriculum materials' role and the students' general learning habits. Theoretical and pedagogical implications are discussed.