We conducted a retrospective analysis on 311 patients with clinical diagnosis of pulmonary embolism (PE) in a period of 3 years. 163 patients were excluded based on clinical-laboratorial criteria. The remaining 146 patients had a median age of 69 years (range: 30-91 years). 54% of the patients were male. We found dyspnea (94%), abnormal cardiopulmonary observation (89%), risk factors for venous thromboembolism (74%), tachycardia (53%), cyanosis (49%), and neck vein distension (45%) to be the most frequent findings. 64% of the patients had heart failure, 32% had myocardial ischemia, 13% had cancer, and 11% had myocardial infarction. Lactic dehydrogenase (LDH) was higher than two-fold in 54% of the patients. There was severe hypoxemia in 55% of the cases and hypocapnia in 43% of the cases. Creatinine phosphokinase (CPK) was elevated in 16% of the cases. Electrocardiography was suggestive of PE in 37% of the cases. Echocardiography showed right heart dysfunction in 30% of the cases, 92% of the patients were treated with heparin, 37 patients (25%) died, 54% of which during the first 4 days after admittance. Trying to define an index of mortality in PE we evaluated all patients by discriminant analysis coming up with 14 items with good discriminative power. By approximation of their odds-ratios we determined how many points would correspond to each item in the total sum.(ABSTRACT TRUNCATED AT 250 WORDS)