ABSTRACT This article discusses the professional identity of teachers, based on the analysis of the final reflections of four masters students at the University of Lisbon, seeking to understand the conceptions of professional identity of these future teachers of secondary school science. This analysis uses a qualitative methodology focused on a narrative perspective. In their reflections, these future teachers refer to the importance of the learning that they made in the supervised teaching practice and their contribution to their professional development. These narratives, written in the first person, express the students’ perceptions about their evolution during the initial training process and highlight their professional identities at the end of this training cycle. This evolution stems from their teaching and non-teaching experiences and reveals different degrees of consolidation of their professional identities.