Introduction: Massive Transfusion Protocol (MTP) activation allows for efficient delivery of a balanced transfusion strategy to exsanguinating patients, and should deliver a reasonable ratio of plasma and platelets to red blood cells. MTP activation should facilitate communication between care providers and laboratory services in order to minimize blood product wastage. Unfortunately, it is unclear which activation criteria are best to achieve this. Understanding of acceptable sensitivity and specificity, as well as reasons for blood component wastage, may provide refinement to MTP design. Methods: We surveyed clinicians, who were identified as content experts in their fields, using a snowball survey technique. Respondents were categorized into two groups: Group 1 included Emergency Medicine, Anesthesia, Critical Care, and Surgery; Group 2 included Hematology, Hematopathology and Transfusion Medicine. Between-group differences were examined using the Pearsons Chi-Square Test. Statistical significance was set at p<0.05. Results: 50% of physicians in Group 1 considered an MTP under-call rate of 5-10% to be acceptable, whereas the majority (57.1%) of physicians in Group 2 considered an under-call rate of <5% to be acceptable. Both groups agreed on an acceptable over-call rate of 5-10%. A significantly greater proportion of physicians in Group 1 felt that MTP activation criteria including transfusion of an entire blood volume within 24 hours, loss of >50% blood volume within 3 hours and anticipated transfusion of >10U of PRBC in 24 hours were appropriate for MTP activation. Physicians in Group 2 were more likely to consider poor communication a reason for blood component wastage. Conclusion: Similarities in acceptable over- and under-call rates of MTP highlight the similar values in MTP activation between different medical specialties. Collaboration between the resuscitation team and consultants in transfusion medicine is necessary for MTP protocol development to improve patient outcomes and reduce blood wastage.