The study focuses on pre-service teachers’ reflection processes in four different contexts during their subject teaching practicum: (1) reflections on lessons, (2) pupil observation, (3) research reading, and (4) autobiographical context. The data consist of 53 pre-service teachers’ mathematics portfolios, from which the authors purposively selected three for closer scrutiny. According to the results, the breadth and depth of the pre-service teachers’ reflection processes greatly varied. Furthermore, the mathematics autobiographies revealed how the students had constructed their mathematics pasts and what they had learnt from their earlier experiences of teaching mathematics.