Most research into research supervision practice focuses on functional, collegial or problematic power-related experiences. Work developing the supervisory role concentrates on new supervisors, and on taught development and support programmes. Most literature on academics' professional learning concentrates on learning to be a university teacher and, latterly, a researcher. However, the research supervisor's role is constantly evolving in response to experiences with students, and reflection on this can contribute to professional learning. Initial research suggests examiners learn from examining experiences feeding back into supervisory roles. We argue that being a thesis examiner provides academic staff with opportunities to learn about their own supervisory practices, enhancing their professional learning. Our research reports on examiner perceptions of learning from examining doctoral theses, which can be taken back into supervisory practice, and translated into advice for other supervisors and doctoral students.