This article describes the complexity of the preservice secondary school mathematics teachers' experiences in their use of action research as a tool provided for them in the teacher education program. It also examines what do the teacher educators learn about their repertoires and those of their students as they develop the research project within and across the disciplines. The findings show that the participants built trust overtime, which helped them to share their challenges with their instructors. The instructors realized that there needed to be a stronger connection between the PSSM teachers’ content knowledge and pedagogical content knowledge. The participants had hands-on experience and they are more confident to continue doing action research and become more reflective in their own classrooms. Furthermore, they enhanced their skills for students’ mathematics learning context.