Transfusion-related acute pulmonary edema (TRALI) is a transfusion-related incident whose etiology and pathophysiology are still debated suggesting immunological or non-immunological mechanisms following leukocyte activation by biological response modifiers (BRMs) supplied by transfused labile blood products (LBP).Using 4 cases of TRALI reported to the haemovigilance unit of the Sfax CRTS we discuss epidemiology pathophysiology positive and differential diagnosis management and primary and secondary prevention.