This study offers insights into processes that play a role in realizing curriculum flexibility through the implementation of a blended curriculum. Curriculum flexibility is conceptualized in terms of adaptability and accessibility to students’ needs and capabilities. In order to realize curriculum flexibility, the teacher training institution in this study designed a blended curriculum with face-to-face and online components. This flexible blended curriculum aimed at increasing student enrolment and offering variety in students’ graduation profiles. Based on an analysis of formal curriculum materials, flexibility of the intended and formal curriculum was determined. Through subsequent semi-structured interviews with ten teacher educators, fostering and inhibiting factors regarding realizing flexibility were identified. Results show that the teacher educators perceived the formal curriculum as less flexible than intended. Furthermore, they identified different contextual, teacher- and student-related factors that affected (further) flexibilization. Based on a discussion of these findings, recommendations for research and practice are given.