Mentoring should not be seen as exclusively a one-way process in which the 'expert' mentor guides the 'inexpert' and 'deficient' learner. Any learning that takes place should have a dimension of mutuality. We report here on an enquiry in which an experienced PGCE history tutor (Peter) and a new PGCE mathematics tutor (Chris) engaged as part of a three-year TVEI in ITT staff development project (1988-91) in the Division of Education, Sheffield University. We offer this analysis of our experience in the belief that it suggests points that might usefully be considered by mentors in schools, where some of the background factors may well be replicated: ie, adult trainees teaching different subjects from those who are mentoring them, teaching those subjects within an organization which has an explicit rhetoric, and participating (formally or informally) with fellow trainees from other subject areas in professionally focused discussion.