Blood coagulation and fibrinolysis were studied in 20 premenopausal women undergoing abdominal hysterectomy under general anaesthesia (GA) or high epidural analgesia (EDA). As expected, the adrenocortical stress response was suppressed in the EDA group. The Factor VIII complex (F VIII:C, F VIII R:Ag = von Willebrand factor), known to be related to adrenocortical activity and/or vessel wall reactivity, was found to increase less in the EDA group. With regard to all the other variables analysed there were no significant differences between the groups. With both anaesthetic procedures activation of coagulation could be demonstrated by a decrease in prekallikrein, F X and antithrombin as well as by an increase in fibrinopeptide A levels. A decrease in plasminogen and alpha 2-antiplasmin suggested activation of the fibrinolytic system and a decrease in prekallikrein and kallikrein inhibition activity (C-1-esterase inhibitor) an activation of the kallikrein system. In this study only the differences in F VIII complex could explain the previously reported higher thromboembolic frequency after GA as compared to EDA.