Book excerpt: Continuous professional development of chemistry teachers is essential for any effective chemistry teaching due to the evolving nature of the subject matter and its instructional techniques. Professional development aims to keep chemistry teaching up-to-date and to make it more meaningful, more educationally effective, and better aligned to current requirements. Presenting models and examples of professional development for chemistry teachers, from pre-service preparation through to continuous professional development, the authors walk the reader through theory and practice. The authors discuss factors which affect successful professional development, such as workload, availability and time constraints, and consider how we maintain the life-long learning of chemistry teachers. With a solid grounding in the literature and drawing on many examples from the authors' rich experiences, this book enables researchers and educators to better understand teachers' roles in effective chemistry education and the importance of their professional development.