© 2021 Georg Thieme Verlag. All rights reserved.Background Thrombin-activatable fibrinolysis inhibitor (TAFI) inhibits fibrinolysis and high levels may have an association with thrombosis. The aim of the current study was to investigate the association of TAFI antigen levels with pulmonary thromboembolism (PTE). Patients and Methods A case-control study was conducted with 29 patients with PTE and 17 age- and gender-matched control individuals. Plasma levels of TAFI were measured at the time of diagnosis, then at 3 and 6 months after the event. Results Initial TAFI levels (%) were higher in patients with PTE than in the control group Initial TAFI levels (%) were higher in patients with PTE than in the control group (190,0 [65,0-250,0] vs 133,0 [83,0-153,0]; p = 0.003). TAFI levels significantly decreased at the third and sixth months after initial diagnosis (p < 0.05). The percentage reductions in TAFI levels were 12 and 36.8% at 3 and 6 months, respectively. The Odss ratio (OR) of TAFI level for PTE was found to be 1.024 (95% CI: 1.007-1.040; p = 0.005). There was no significant correlation of initial TAFI levels with age, gender, smoking status, history of thrombosis, pulmonary artery pressure, and D-dimer levels (p > 0.05). In the sixth month of treatment, patients with residual thrombosis were seen to have similar baseline levels and reductions of TAFI as patients without residual thrombosis (p > 0.05). Conclusion The result of this study suggests that high TAFI levels may have a role in the occurrence of PTE without impact on treatment outcome.