Research on coopetition has largely been based on collaborative relationships between competitors. Building on this body of knowledge and addressing recent calls for research on intra-organizational and emergent coopetition, the purpose of this paper is to further our understanding in regard to these issues. The study is based on an in-depth qualitative study at the Emergency Department of Umeå University Hospital and consists of more than 80 hours of participant observation and interviews. The paper analyses the collaborative and competitive practices that exist among medical doctors and nurses, and discusses what seems to be triggering intra-organizational coopetition and its consequences. The analysis illustrates that coopetition emerges among individuals and groups not necessarily as the result of the implementation of an intended strategy. On the contrary, triggers of emergent intra- organizational coopetition include the organizational structure, diversity of professions, division of work activities, availability of resources, uncertainty and workload levels. All this makes a distinct contribution to the understanding of intra-organizational coopetition as an emergent practice, knowledge that should be of use from both a theoretical and a practical point of view.