We examined vascular endothelial cell markers, thrombomodulin (TM), plasminogen activator inhibitor-I (PAI-I), tissue plasminogen activator (t-PA), and von Willebrand factor, in 80 patients with disseminated intravascular coagulation (DIC). The levels of thrombin-antithrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC) and FDP-D-dimer were significantly increased both before and after the onset of DIC, but were not correlated with organ failure or prognosis. However, the PIC/TAT ratio was lower in patients with poor prognosis than in those with good prognosis, and it was also lower in those with organ failure than in those without. Plasma TM, PAI-I, and t-PA levels were increased in DIC patients with organ failure or poor outcome, but were not significantly increased before the onset of DIC. We consider that the prognosis of patients with DIC might be related to organ failure or endothelial cell damage and that plasma levels of TM, PAI-I, and t-PA might be useful in the detection of these disorders and in assessing prognosis. A hypofibrinolytic state might enhance organ failure in patients with DIC.