In order to investigate changes in coagulation and fibrinolysis arising during and after laparoscopic surgery we studied 24 patients, who were operated on because of biliary lithiasis [21 females, three males, aged 36-69 (mean 50) years]. The reference group consisted of 17 patients, who were operated on traditionally [15 females, two males, aged 25-72 (mean 55) years]. Blood samples were taken from cubital vein 24 h prior to the operation, during the cholecystectomy, on the 1st and 3rd postoperative days. Additionally, before and during operation blood was sampled simultaneously from femoral vein. Both groups had similar perioperative values of platelet count, fibrinogen and t-PA Ag. Patients operated on laparoscopically had generally lower values of F1 + 2 and plasmin-alpha 2-antiplasmin complexes, and intra-operative PAI-1 activity than those operated on traditionally. Test values in blood sampled simultaneously from femoral and cubital veins were not statistically different. The data obtained show that generation of thrombin and plasmin is lower in patients operated on laparoscopically compared with those having traditional surgery. Venous stasis during laparoscopic cholecystectomy in lower extremities does not cause local alterations in hemostasis.