GP training in the UK has a long history of success, however that is measured. That success is in part due to the formality and credentialling that underlies preparation to take on that role of a GP teacher, which is somewhat under current threat due to workforce pressures. We identify three important factors associated with the GP trainer function [leadership, professional identity and clinical care improvement] that are not often analysed but are at some risk if preparation for the GP trainer role is reduced or devalued. Of particular note are the differing ways that GPs conceptualise their professional roles as teachers and clinicians, despite the transferable skills between them, the demonstrably improved patient care that occurs in practices that teach, and the necessary connections between educational theory and practice. We suggest that these areas define a research agenda ripe for exploration.