This research poster provides the reader with information regarding an ethnographic study that explored the lived experiences of mental health and emergency department (ED) nurses in regards to the triage process of people who presented with a mental illness to an ED. The design enabled a better understanding of the interdisciplinary relationships between mental health nurses and ED triage nurses that are necessary to sustain an emergency mental health triage service to clients presenting with a mental illness. Results, which contribute new knowledge to this field, identified that the relationship between ED triage nurses and metal health triage nurses is predicated upon a number of inter-related yet at times seemingly competing factors. These factors were identified as 1) environment 2) assessment 3) presence 4) collegiality and 5) roles and scope of practice. These themes are influenced by both intrinsic and extrinsic factors. Intrinsic factors include: pre-existing knowledge, experience as a nurse, level of training, previous experience with clients who have a mental illness, as well as personal and professional standards of practice. Extrinsic factors include: ED architecture, geography of the triage setting, departmental and institutional policies and procedures, established processes of communication between disciplines and professional practice standards of both the mental health nurses and the ED triage nurses. The cultural milieu that defines the discipline areas of the two groups of nurses and the complex interplay of these factors emerged as a central construct and has a profound influence on the practice of each nursing discipline and the relationship that exists between them.