There is suggestive evidence that both the coagulation and the fibrinolytic systems are activated in trauma and in shock. Trauma and shock may be complicated by systemic deposition of fibrin within the vascular tree (disseminated intra-vascular coagulation, DIC). The occurrence of DIC is often observed when the enhancement of coagulation is not balanced by a correspondent enhancement of fibrinolysis. Defective stimulation of fibrinolysis is observed in conditions accompanied by suppression of the fibrinolytic system, such as in pregnancy and after administration of fibrinolytic inhibitors. DIC after trauma and shock is presumably more common in subjects who usually respond poorly to fibrinolytic stimuli (the so-called poor responders) than in ‘normal responders’. The same factors which favour the occurrence of DIC seem to have an unfavourable influence also on the final outcome of the complicat