Introduction: Helicopter emergency medical services (HEMS) have become an engrained component of trauma systems to expedite transportation to a trauma centre. Ornge is a provincially run, paramedic-staffed HEMS that is responsible for all air ambulance service within Ontario, Canada. They provide transportation for trauma patients through one of three ways: scene call, modified scene call or interfacility transfer. In this study we report the characteristics of patients transported by each of these methods to two level 1 trauma centres and assess for any impact on morbidity or mortality. Methods: A local trauma registry was used to identify all patients transported to our two trauma centres by HEMS over a 36-month period. Data surrounding patient demographic, arrival characteristics, transport times and in-hospital course were abstracted from the registry. Statistical analysis will be used to compare methods of transport and characterize any association between mode of transport and mortality. Results: From January 1st, 2012 to December 31st, 2014 HEMS transferred a total of 911 patients to our trauma centers with an overall mortality rate of 11%. Of these patients 139 were scene calls with a mortality rate of 8%, 333 were modified scene calls with a mortality rate of 14% and 439 were interfacility transfers with a mortality rate of 10%. Conclusion: Identifying any association between the type of HEMS transport and morbidity and mortality, we may be able to predict those that need more urgent transfer to a trauma centre and find ways to decrease our overall pre-trauma center time.