Introduction: Prehospital blood transfusion has been adopted by many civilian helicopter emergency medical service (HEMS) agencies and early outcomes are positive. Shock Trauma Air Rescue Service (STARS) operates six bases in Western Canada and in 2013 implemented a prehospital transfusion program. We describe the processes and standard work ensuring safe storage, administration, and stewardship of this precious resource. Our aim was to produce a sustainable and safe blood storage system that could be carried on each mission flown. Methods: Close collaboration with transfusion services and adherence to Canadian Transfusion Standards was key at each step of development. An inexpensive, reusable, temperature controlled thermal packaging device was obtained along with an electronic temperature logger. Conditioning of the device and temperature maintenance (1 6C) was tested to ensure safe storage conditions. Online training programs were developed for air medical crew (AMC) as well as transport physicians (TPs) regarding administration indications, safety, and stewardship processes. Blood traceability and usage was monitored on an ongoing basis for quality assurance. Results: Two units of O negative packed red blood cells (pRBCs) are now carried on each flight. The blood box is conditioned and prepared by transfusion services for routine exchange every 72 hours. If pRBCs are administered the blood bank is immediately notified for preparation of another cooler. Unused blood is returned to blood bank circulation. Conclusion: The introduction of the STARS blood on board program supports the provision of emergent transfusion to selected patients in the pre-hospital environment. Our standard work and stewardship processes minimize wastage of blood products while keeping it readily available for critically ill and injured patients. Subsequent work will aim to describe characteristics and patient centred outcomes.