Pedagogical Equilibrium is an innovative reconceptualisation of teachers’ professional knowledge development. The book draws on interview data and in-depth analysis of situations, which challenge teachers’ sense of pedagogical equilibrium in both primary and secondary school contexts. These moments highlight the complexity of teaching and the valuable personal and professional learning opportunities afforded by experiencing and processing moments which create uncertainty during practice. Mansfield considers a variety of aspects of teaching practice, including content knowledge, organising for teaching, organising for learning, and student attitudes and behaviours. Drawing on detailed examples, a new framework is offered to scaffold teacher thinking around moments in practice which can challenge the sense of equilibrium in the classroom. Pedagogical Equilibrium is a highly valuable resource for educational researchers, teacher educators, current teachers and other educational stakeholders.