Framed in action research, the authors investigated the perceptions and experiences of a cohort of student-teachers as they learned about and explored for the first time teacher research in a self-contained module as part of a four-year pre-service or initial English language teacher education (IELTE) programme in southern Argentina. The module, 'Research in English Language Teaching', ran from March-November 2018. It was led by a teacher educator based in Argentina and a UK-based colleague who acted as an external academic advisor. Drawing on qualitative research, data collection strategies included: the tutor's journal; student-teachers' journals; assignments; research proposals; report drafts; presentations; group discussions; interactions between the tutors; and end-of-course interviews. The findings show that the module had a positive effect on student-teachers' identity, their English language proficiency, and the role of reflection in feedback processes. The student-teachers appreciated teacher research as reflective practice and as a source of professional development.