Extensive reading has been widely known for its benefits for language learners’ competence. However, there is little research on teacher professional development research on ER. This study aims to address this gap by offering an autoethnographic account of my professional Extensive Reading (ER) development. The data of this study were taken from my teaching materials, epiphanies, reflections, questionnaires, as well as document analysis of my community services, where I worked with many teachers to better understand and implement ER in their teaching contexts. In my autoethnographic study, I described my personal experiences as well as the lessons I learnt from my continuous involvement in ER learning, teaching, and research. This study aims to make a valuable contribution to the ongoing discourse surrounding the construction of ER teacher identity and is likely to resonate with educators interested in implementing ER in their own teaching contexts.