Introduction / Innovation Concept: During Emergency Department (ED) resuscitation of critically ill patients, effective teamwork and communication among various healthcare professionals is essential to ensure favorable patient outcomes and to minimize threats to patient safety. However, numerous individual and system factors create barriers to effective team functioning. Simulation center- based training has been used to improve Crisis Resource Management skills among physician and nursing trainees, but in-situ simulation is a relatively new concept in adult Emergency Medicine in North America. Methods: To enhance patient care and team effectiveness, an ED nursing and physician group was created to develop and implement a novel interprofessional in-situ simulation program in two Canadian, academic tertiary-care emergency departments. Departmental approval and financial support was obtained and sessions commenced in January 2015. Curriculum, Tool, or Material: Monthly high-fidelity simulation sessions are held in the ED resuscitation rooms at both campuses of our hospital. Each session is facilitated and debriefed by simulation-trained Emergency Medicine faculty and senior residents, a nurse educator and a research assistant. Technical support is provided by our simulation center staff. Participants are recruited from the physicians, residents, nurses, respiratory therapists and other support staff working in the ED. To minimize the impact on patient care, two additional nurses are scheduled to cover nursing assignments on “sim days”. Simulations are limited to fifteen minutes, followed by a twenty minute debriefing. Conclusion: We have successfully developed and implemented an interprofessional in-situ simulation program in our ED. Participant feedback has been overwhelmingly positive. Lack of financial support, reluctance of staff to participate, and overwhelmed resources are some of the challenges to running a program like this in a busy ED environment. However, there are clear benefits: empowering team members, culture change, identification of latent safety threats, and a perception of improved teamwork and communication.