Although teacher beliefs are well-researched in the second language teacher education field, most studies used survey methods to identify teachers' beliefs rather than examining the relationship between beliefs and instructional practice. Recently, research on second language teaching placement has focused on how the realities of the placement shape the development of preservice teachers' beliefs. However, how preservice teachers' prior beliefs influence their professional learning during the practicum remains underexplored. Given the widely acknowledged importance of teacher beliefs in the work of language teachers, this gap needs to be filled. Underpinned by a sociocultural perspective on teacher learning and drawing primarily on data from interviews, the qualitative case study reported in this chapter investigated the pedagogical beliefs that three preservice English as an additional language (EAL) teachers had during their school-based placements in Australia and how these influenced their professional learning during the placement. The study found that beliefs related to language teaching and learning played an influential role in shaping the preservice teachers' professional experiences, and the influence manifested differently across the three participants due to the interface between their beliefs and other personal and contextual factors. The findings offer implications for supporting preservice EAL teachers in effectively socialising into the profession. [For the complete volume, "Transforming Pedagogies through Engagement with Learners, Teachers and Communities. Education in the Asia-Pacific Region: Issues, Concerns and Prospects. Volume 57," see ED661742.]