This paper reports the findings of a narrative study on language student teachers' epistemological reconfigurations through lesson planning in a private university in Bogota, Colombia. The study aimed at exploring the possible forms of professional yet personal-local knowledge two language student teachers encounter and produce when they plan language lessons. We employed the life story interviewing to gather information on the subjective essence of the participant's experiences in their teacher practicum. Findings suggest that through lesson planning, language student teachers manage to re-signify certain methodological yet hegemonic constructions of teaching and learning. Furthermore, their knowledge of themselves as teachers in relation to their practicum is shaped by circumstances they face in the process of planning and teaching lessons.