Thirty-three patients with chronic uremia on regular hemodialysis treatment (RDT) have been studied to determine whether coagulation and fibrinolysis are enhanced or not. We examined predialysis values of coagulation and fibrinolysis parameters including alpha-2-plasmin inhibitor-plasmin complex (alpha 2PIC), a good index of in vivo plasmin production, and cross-linked fibrin degradation products (XL-FDP), an index of fibrinolysis secondary to coagulation. Fibrinogen was significantly higher (p less than 0.001) in RDT patients than in normal controls. ATIII activity was significantly lower in RDT patients than in normal controls (p less than 0.001). Plasminogen activity and alpha-2-plasmin inhibitor (alpha 2PI) activity were significantly lower (p less than 0.001) in RDT patients than in normal controls. Alpha 2PIC and XL-FDP were both significantly higher (p less than 0.001) in RDT patients than in normal controls. XL-FDP was inversely correlated with alpha 2PI (r = -0.486, p less than 0.01) and positively correlated with alpha 2PIC (r = 0.646, p less than 0.001). These results suggest that coagulation and fibrinolysis are enhanced in RDT patients and that the enhanced fibrinolysis is mainly due to fibrinolysis secondary to coagulation.