While it is well established that platelets are integral to hemostasis, more recent evidence points to an important role for platelets in inflammation and immunity. Platelet activation and sequestration in pulmonary tissue is a key feature in inflammatory or infectious states such as sepsis and acute respiratory distress syndrome (ARDS). Platelets may mediate acute lung injury (ALI) by recruiting neutrophils, triggering neutrophil extracellular DNA nets, and releasing granule contents and microparticles. Anti-platelet therapy in this setting may prevent platelet activation, platelet - leukocyte aggregate formation, and inflammation.