Introduction: The Queen Elizabeth II Health Sciences Centre (QEII HSC) is a Level I trauma center that provides tertiary care services to the province of Nova Scotia (pop. 940,592) and quaternary care services to Atlantic Canada (population > 2.4 million). The objective of this study was to describe and evaluate the development of an inter-professional hospital-wide trauma simulation that was performed at the QEII HSC in June of 2015. Methods: The simulation was performed in the dedicated trauma resuscitation bay in the emergency department of the trauma centre using SimMan equipment. The scenario involved a 35-year-old male pedestrian versus car at approximately 70 km. The patient required immediate resuscitation and transfer to the operating room for an emergency laparotomy. Evaluation of the simulation was through video feedback, time stamping, piloting of resident Trauma Team Activation evaluation, observation for latent safety issues, and participant feedback. Trauma team members were unaware of simulation prior to arrival. Results: Feedback received from simulation participants indicated that this exercise was incredibly “real” for them. Using the usual emergency department patient registration proved difficult in this simulation exercise, both for activation of the massive transfusion protocol and transfer of the patient to the operating room. Latent safety issues identified included a lack of communication with the operating room and unavailability of some resuscitation equipment. Debriefing after the event was felt to be important by all participants of the simulation. Having evaluators dedicated to observing specific aspects of the simulation would facilitate these exercises. Patient care was not interrupted in the emergency department or the operating room. Conclusion: The in situ simulation was a valuable experience for the trauma program, stakeholders, and all participants. Based on this trial simulation, additional simulations will be held within our trauma program. Further research is required to validate long-term retention of skills and knowledge, and to evaluate the impact of simulation training on staff performance and trauma patient outcomes.