As teachers are at the heart of education, a substantial number of studies have researched the perception that mainstream school teachers have of themselves in relation to their work. This investigation extends this field of inquiry by examining how teachers' self-understanding is altered when they transfer from mainstream to special school education. This study adopts the methodology of interpretive phenomenological analysis (IPA) to examine in detail how three female teachers in inner London experienced the transition from mainstream secondary schools to teaching in alternative provision for excluded students referred to as a pupil referral unit (PRU). Central to IPA is how an individual experiences a substantial change in life and the influence this may have on his or her world views. The research approach adopted is, therefore, idiographic and reliant on the experiences of a small number of participants. The findings from this investigation indicate that the participants chose to leave mainstream school education when they came to the self-realisation that they wanted to engage in more creative and personally engaging professional practice with a stronger moral purpose. When they started to teach at a PRU, the more persistent and personal relationships with their students brought about a substantial change in self-understanding.