This paper aims to scrutinize the trajectory of the professional identity configuration of Indonesian EFL pre-service teachers in socialization during a two-month teaching practicum at a private school in Yogyakarta, Indonesia. Two female EFL pre-service teachers carrying out a teaching practicum at the school participated in this study. A narrative inquiry was employed to capture the dynamic development of the professional identity configuration from the participants' points of view. The researchers developed stories based on participant interviews, daily reflective notes, and weekly conferences. The stories were then analyzed to identify the professional identity configuration. The findings suggested that the participants configured their professional selves as EFL teachers in socialization in the school through identification and self-internalization. Their identification was influenced by how they saw themselves and others viewed them as EFL teachers, which was then internalized as self-concepts. Moreover, the socialization process encouraged the student teachers to construct their professional selves, reflected in the emerging themes of the stories: language-, pedagogy-, organizational role-, and spirituality-driven identities. The findings also highlighted that spaces, artifacts, and positioning influenced how the pre-service teachers made meaning of their professional selves. The researchers emphasized the importance of reflection to facilitate the meaning-making of EFL preservice teachers' professional selves by contemplating their professional socialization experiences during the practicum.