Background: Pulmonary embolism (PE) is a common clinical problem in the West that is associated with substantial morbidity and mortality. The diagnostic modality has been changed since 2001. This study retrospectively reviewed the PE mortality with the aim of identifying the risk factors associated with mortality since the multidetector computed tomography (MDCT) was introduced. Methods: We analyzed 105 patients with acute PE proven by multidetector CT or ventilation perfusion scan. The primary outcome measure was the all-cause mortality at 3 months. The prognostic effect of the baseline factors on survival was assessed by multivariate analysis. Results: The main risk factors were prolonged immobilization, stroke, cancer and obesity. Forty nine percent of patients had 3 or more risk factors. The overall mortality at 3 months was 18.1%. Multivariate analysis revealed low diastolic blood pressure and the existence of cancer to be independent factors significantly associated with mortality. Forty two PE patients were examined for the coagulation inhibitors. Four of these patients had a protein C deficiency (9.5%), and 11 had a protein S deficiency (26%). Conclusion: PE is an important clinical problem with a high mortality rate. Close monitoring may be necessary in patients with the risk factors.