Transfusion-related acute lung injury (TRALI) has insidiously become the leading cause of transfusion-related deaths in the United States and most other developed countries. It was often only recognized thanks to the Serious Hazards of Transfusion (SHOT), a British haemovigilance system. It noted an upward trend in deaths occurring after a transfusion and characterized by pulmonary complications. Although experts and key stakeholders in the field are continually convened to define a consensus definition of TRALI, the current operational definition of TRALI is a life-threatening adverse transfusion effect characterized by the development of acute respiratory distress with hypoxemia during or beyond 6 hours after completion of a blood transfusion. The first documented case of TRALI dates back to 1951. In this original case, TRALI was described as a hypersensitivity causing pulmonary complications (1). Other encounters with TRALI produced a number of other descriptive terms until 1985, when the Mayo Clinic invented the word TRALI to define acute respiratory distress with pulmonary edema following transfusion of blood or blood products. The first death due to TRALI was reported to the Center for Biological Evaluation and Research (CBER) in 1992. Since then, the number of deaths caused by TRALI has gradually and steadily increased. Between 1992, when the first death was reported, and fiscal year 2000, there were 45 additional deaths. The latest CBER data for the 2008-2012 fiscal year confirms that there have been 74 deaths caused by TRALI. A rather alarming peak. The increase in TRALI deaths in the United States and the lack of a clear definition required intervention by the National Heart Lung and Blood Instit...... middle of document ......ates and RBC.8. Toy P, Jun J, Hollis-Perry M, et al: Recipients of blood from a donor with multiple HLA antibodies: a blinded study of TRALI. Transfusion 2004; 44:1683–1688.9. Covin, R.B., Ambruso, D.R., England, KM, Kelher, M.R., Mehdizadehkashi, Z., Boshkov, L.K., Masuno, T., Moore, E.E., Kim, F.J. & Silliman, C.C. (2004) Hypotension and acute pulmonary failure in continued Transfusion of autologous red blood cells during surgery: description of a case and review of the literature. Transfusion Medicine, 14, 375–383.10. Rizk A, Gorson KC, Kenney L, Weinstein R. Transfusion-related acute lung injury after IVIG infusion. Transfusion. 2001; 41:264-268.11. Chapman, C.E., Williamson, L.M., Cohen, H., Stainsby, D. & Jones, H. (2006) The Impact of Using Male Donor Plasma on Haemovigliance Reports of Transfusion Related acute Lung Injury (TRALI) in the UK.