The University of Ottawa in Canada offers a peer-mentoring program (whereby an experienced student provides support and guidance to another student) and an associated training program for all peer mentors through its Student Academic Success Service. In addition to the formal training, some peer mentors receive feedback and support through an electronic journal system that records communication between mentors and their supervisor, a paid employee of the university. As a transcript of the interaction between those peer mentors who use the journal and their supervisor, and a record of the mentor's competency development, the journals provide a rich source of data. This project used an in-depth content analysis of 192 journals in order to assess the learning process experienced by the mentor. Using reflection-on-action as a theoretical framework, this study explores the processes involved as peer mentors reflect on and assess their own practices, and examines the role of dialogue, in the form of feedback provided by the supervisor, in this learning process.