Abstract: The present invention relates to a complex (tcuPA/suPAR) of the two chain urokinase plasminogen activator (tcuPA) with the soluble urokinase plasminogen activator (suPAR), to pharmaceutical compositions comprising this complex and to different uses of the compositions in the treatment and/or prevention of thrombotic events, particularly those associated with the formation of fibrin clots. In the complex (tcuPA/suPAR), the suPAR stimulates firbrinolytic activity mediated by tcuPA under physiological conditions. The complex acts preferably on freshly-formed clots and is specific to such clots.