This qualitative study provides a critical case to analyse the identity development of professionals who already have a strong sense of identity as scientists and have decided to relinquish their professional careers to become teachers. The study followed a group of professionals who undertook a one-year teacher education course and were assigned to secondary and middle-years schools on graduation. Their experiences were examined through the lens of self-determination theory, which posits that autonomy, confidence and relationships are important in achieving job satisfaction. The findings indicated that those teachers who were able to achieve this sense of autonomy and confidence, and had established strong relationships with colleagues generated a positive professional identity as a teacher. The failure to establish supportive relationships was a decisive event that challenged their capacity to develop a strong sense of identity as a teacher
