The identification and management of coagulopathy is a critical component of caring for the severely injured patient. Notions of the mechanisms of coagulopathy in trauma patients have been supplanted by new insights resulting from close examination of the biochemical and cellular changes associated with acute tissue injury and hemorrhagic shock. Acute intrinsic coagulopathy arising in severely injured trauma patients is now termed trauma-induced coagulopathy (TIC) and is an emergent property of tissue injury combined with hypoperfusion. Mechanisms contributing to TIC include anticoagulation, consumption, platelet dysfunction, and hyperfibrinolysis. This review discusses current understanding of TIC mechanisms and their relative contributions to coagulopathy in the face of increasingly severe injury and highlights how they interact to produce coagulation system dysfunction.