In exploring imposter feelings in early career academics, this article examines the impacts of adopting social constructivist pedagogies. It reveals the significance of reflective practice in a Post-Graduate Certificate in Academic Practice programme (PGCAP), supporting professional development in teaching, learning and assessment for new academics in a UK Higher Education context. A qualitative case study approach enabled researchers to gain insight into participants' experiences; data was collected via semi-structured interviews. Findings suggest that causes for imposter feelings are multi-faceted, encompassing factors including interactions with students, and adjusting to university language, culture and systems. Alongside similar studies internationally, the authors present that employing social constructivist pedagogical tools in a planned programme of professional development for early career academics supports the creation of mutually empowering communities of practice (CoP), so addressing threats to professional identity, providing a horizontal alternative to organisational hierarchical support mechanisms, and enabling the construction of a secure academic identity.