This paper reports on the findings from a review of classroom-based action research reports by the masters students of an in-service teacher education programme offered by the Aga Khan University, Institute for Educational Development in Karachi, Pakistan. In these reports the students played the roles of researchers and mentors, i.e. they worked as mentors with teachers in a school, researched the process of mentoring and reported the findings. I undertook this review to report findings related to impact on schools and classrooms of new approaches to teacher development. While, the findings stopped short of reporting impact of mentoring on classrooms, it revealed significant issues pertaining mentors' roles. There was tension in how these roles were conceptualized within the masters programme and how they were enacted. For example, the mentors were expected to work in a generalist role as mentors, i.e. to work with teachers irrespective of the discipline that the teachers taught. However, experiences from the field showed that perceptions of mentor as a subject specialist dominated the process of mentoring. The paper also reports on other issues pertaining to mentor-mentee interactions in the context of in-service teacher education in a developing country setting.