This article reports a small-scale experiment of a strategy designed to support the sharing of academic expertise at a Distance Learning University. Two small and separate groups of academic staff members (one of four professors and one of five instructional designers, both including experienced and new employees) volunteered to meet regularly, over a one-year period, to elaborate a collective knowledge map representing a portion of their professional knowledge. This tool- and peer-mediated mentoring activity created a professional learning context in which participants were encouraged to externalize and thus share some tacit knowledge developed through professional practice, as well as explicit but sometimes ambiguous organizational knowledge. The data analyzed so far includes audiotaped individual interviews conducted before and at the end of the experiment, audiotaped group debriefings at the end of each meeting and the knowledge map constructed in each group. Results suggest that combining group mentoring with collaborative knowledge modeling is a promising strategy to foster the elicitation of professional expertise and thus support the professional development of academic staff in universities. This strategy can be defined as an intentional but non-formal professional learning activity that fits well with conceptualisations of learning at the workplace as both a knowledge participation process and a knowledge creation process.