Developing professional identity is a vital part of health professionals' education. In Auckland four tertiary institutions have partnered to run an interprofessional simulation training course called Urgent and Immediate Patient Care Week (UIPCW) which is compulsory for Year Five medical, Year Four pharmacy, Year Three paramedicine and Year Three nursing students. We sought to understand student experiences of UIPCW and how those experiences informed student ideas about professional identity and their emergent practice as health professionals within multidisciplinary teams. In 2018, we commenced ethnographic research involving participant observation, field notes, interviews, photography and observational ethnographic film. A total of 115 students participated in this research. The emergent findings concern the potentially transformative learning opportunity presented within high fidelity multi-disciplinary simulations for students to develop their professional identity in relation to peers from other professions. Our work also exposes the heightened anxiety and stress which can be experienced by students in such interdisciplinary simulations. Student experience suggests this is due to a range of factors including students having to perform in front of peers and staff in such simulation scenarios when their own professional identity and capabilities are still in emergent stages. Staff-led simulation debriefs form a critical success factor for transformative learning to be able to occur in any such simulations so that students can reflect on, and move beyond, the emotion and uncertainty of such experiences to develop future-focused concepts of professional identity and strategies to support effective interprofessional teamwork.