Mentoring in pre-service teacher education has gained prominence in Australia in recent times. In the context of pre-service teacher education, mentoring occurs during the pre-service teacher’s professional placement. The professional placement involves a pre-service teacher being placed with a classroom based mentor teacher in order to learn and practice the craft of teaching. The professional placement is reported as the most valuable part of learning to teach by pre-service teachers, however the success of the placement is dependent on the teacher mentor and their ability to mentor the pre-service teacher. This paper investigates the role of professional development in the training of mentor teachers. Specifically, the paper investigates the types of teaching and learning materials used during professional development sessions with mentor teachers and the impact of these materials on the mentoring approach used by the mentor teacher. As such, the research reported on in this paper, focuses on what mentor teachers conveyed as the most effective aspects of the professional development and how different types of learning materials contributed to their learning.