Thrombolytic therapy (TLT) is currently the most effective method of treatment of ischemic stroke (IS) in the first 4.5 hours. The effectiveness of thrombolytic therapy depends on a number of indicators of the coagulation system. The aim of this study was to clarify the role of plasminogen activator inhibitor type 1 (PAI-1) and D-dimer in predicting the efficacy of thrombolytic therapy and their relationship with the concentration of fibrinogen. Material and methods. The study included 26 patients with IS and held by TLT. Fibrinogen concentration was determined by the method of Clauss, the concentration of PAI-1 and D-dimer were determined by enzyme-linked immunosorbent assay before the TLT and in the dynamics of 2, 3, 5 and 7 days. Results. The concentration of fibrinogen in patients the source was within the reference interval. A statistically significant reduction of fibrinogen concentration by 46.6% identified 2 hours after carrying out TLT. In patients with regredient over baseline was observed, the concentration of PAI-1, above reference values, and for 4 hours after TLT was expressed statistically significant (p<0.001) decrease almost 10 times the level of PAI-1. In patients with progredient course of the source was observed statistically significantly lower at 2.7 times the concentration of PAI-1 than in patients with regredient over (p=0,026), and within 4 hours after TLT was also statistically significant (p<0.001) decreased more than 20 times from the original values. The concentration of D-dimer in patients with regredient over baseline was 2.3 times significantly higher (p=0,049) than in patients with progredient course. Within 4 hours after TLT was a marked increase in the level of D-dimer in both groups at 18 and 28 times (p<0.001). The initial concentration of fibrinogen in patients with IS and TLT directly correlates with the concentration of PAI-1 and D-dimer, as well as associated with the direction and strength of the relationship between PAI-1 and D-dimer in the evaluation of total correlation. Conclusion. Elevated levels of PAI-1 and D-dimer in patients with effective TLT may be associated with the previous activation of the parietal fibrinolysis, as a compensatory response to thrombus formation, which was absent in patients with ineffective TLT.