Plasma levels of tissue-plasminogen activator.plasminogen activator inhibitor (t-PA.PAI) complex and active PAI were assayed in 58 cases of disseminated intravascular coagulation (DIC). A significant elevation of both parameters was observed in most cases of DIC, especially in patients with non-Hodgkin lymphoma, sepsis, or some patients with acute leukemia, but no such elevation was observed in patients with acute promyelocytic leukemia (APL). The levels of both parameters were higher in cases of DIC with multiple organ failure (MOF) than in those without MOF. Since no elevation of t-PA.PAI complex was observed in most cases of APL, t-PA did not seem to play an important role in the activation of fibrinolytic system in APL. Active PAI, which reflects the inhibitory regulation in fibrinolytic system, was considered to play a role in the progression of MOF. Plasma levels of active PAI were low in the cases of APL, which had no complication of MOF.