It is well known that the fibrinolytic system actively participates in inflammatory processes. To investigate the role of the urokinase system in atopic allergy, we assessed circulating levels of urokinase-type plasminogen activator (uPA) and its soluble receptor (suPAR) in patients with pollen allergy suffering from allergic rhinitis and asthma during a period of natural pollens exposure. Plasma concentrations of uPA and suPAR were measured in 19 patients sensitized to grass and rye pollens (12 men and 7 women, 18 to 30 years old) who had seasonal allergic rhinitis and concomitant seasonal asthma symptoms, and 23 age- and sex-matched healthy controls, using THE enzyme-linked immunosorbent assay (ELISA) method. There were no significant differences in plasma concentrations of uPA and suPAR between patients and the control subjects. Seasonal allergic airway inflammation is not associated with enhanced release of uPA and suPAR into the systemic circulation.