Pulmonary embolism (PE) is one of the leading causes of cardiovascular mortality, therefore new parameters regarding risk stratification are sought after. In patients admitted for acute PE we investigated associations between the initial coagulation impairment, expressed by prothrombin time international normalised ratio (INR), and parameters reflecting PE severity. Furthermore, in-hospital, 30-day and long-term mortality were also evaluated. The analysis included 848 patients who were divided into two groups: with normal INR≤1.2, and elevated INR>1.2 (252 patients, 29.7%). The group with elevated INR presented higher incidence of tachycardia and lower systolic blood pressure, higher CRP, d-dimer, and NT-proBNP. This group presented higher estimated systolic pulmonary artery pressure (49 IQR39-62mmHg vs 43 IQR32-53mmHg, p<0.001) and shorter pulmonary artery acceleration time (65 IQR55-85ms vs 81 IQR63-102ms; p<0.001). Patients with elevated INR had more often a sPESI of 1 or higher (78%vs60%, p=0.003). Cox regression model revealed that age, leukocyte level, SBP, neoplasm, and INR are associated with higher risk of death (p<0.001). Finally, elevated INR was associated with higher in-hospital (13%vs3%; p<0.001), 30-day (19%vs6%; p<0.001), and long-term mortality (p<0.001). Summing up, elevated INR on admission is frequent in patients with PE, reflects worse clinical condition and is related to PE severity and prognosis.