Every inflammatory process, including that in the course of bronchial asthma may disturb the balance in blood coagulation and fibrinolysis system. The aim of the present study was to evaluate fibrinolysis in patients with bronchial asthma. The study group consisted of 41 patients with bronchial asthma, hitherto untreated (25 women, 16 men, at mean age 37.37 +/- 12.4 years) and 22 healthy adults (control group). In these subjects, the following parameters were established: euglobulin lysis time (ELT), the concentration of tissue plasminogen activator antigen (t-PA Ag), the concentration of urokinase plasminogen activator antigen (u-PA Ag), the activity of plasminogen activator inhibitor type 1 (PAI-1), the concentration of plasmin-antiplasmin complex (PAP) and fibrinogen/fibrin degradation products (FDP). It was found that patients with bronchial asthma had statistically significantly higher mean values of FDP (9.25 +/- 6.7 micrograms/ml vs. 5.0 +/- 5.9 micrograms/ml; p < 0.001), ELT (123.5 +/- 42.7 min vs. 97.4 +/- 27.1 min; p < 0.001), t-PA Ag (8.36 +/- 3.66 ng/ml vs. 5.5 +/- 3.71 ng/ml; p < 0.01) and PAP complexes (250.3 +/- 95.8 ng/ml vs. 193.4 +/- 60.7 ng/ml; p < 0.02). Mean u-PA Ag concentration in patients with bronchial asthma was significantly lower than in control group (0.24 +/- 0.16 ng/ml vs. 0.53 +/- 0.18 ng/ml; p < 0.01). No statistically significant differences were observed as to PAI-1 activity between patients with bronchial asthma and healthy subjects. The results of the present study suggest that increased concentrations of t-PA Ag, PAP and FDP complexes are the evidence for greater activity of fibrinolysis system in subjects with bronchial asthma.