How can teaching construct professional identity? In a large Australian teaching hospital, a support program for trainee paediatricians who themselves conduct clinical (bedside) tutorials for groups of medical students invites them to focus on their professional identities as teachers, separately from their identities as clinicians, and to critically reflect on contemporary approaches to workplace-based medical education. The notion of the Guide emerges in the findings, as the paediatricians meld their clinical and their pedagogical expertise in highly relational and situational judgements.