Becoming a teacher is a process that underlies different aspects and purposes of social interaction and the construction of a professional identity. Student-teachers perception of themselves and their emotional states might differ from what is expected from them or even from their own goals. Therefore, this research attempted to investigate the development of teacher identity formation in Teaching English as a Foreign Language (TEFL) students through their own perception of their professional identity. It was conducted as a case study and the participants were undergraduate students in the last term. An open-ended questionnaire was used to collect data. Practical activities related to teaching and contact with teaching contexts and with students had a positive evaluation on the part of student-teachers regarding the formation of their identity as teachers. This research demonstrates the importance of the practice in the context of teacher training for the establishment and maturation of teacher identity.