This article discusses state-of-the-art techniques for predicting risk of death after acute pulmonary embolism (PE), with special attention to how underlying malignancy adversely affects survival after an episode. Current methods of risk stratification generally categorize patients with PE as low-, moderate-, and high-risk for in-hospital adverse outcomes of respiratory failure, circulatory shock, and death. Published risk stratification studies find that patients with PE and an underlying malignancy have a worse prognosis, but no validated risk stratification criteria have been published specifically for these patients. Standard treatment is full-dose heparin followed by oral anticoagulation. The term escalated treatment refers to the use of systemic or intrapulmonary fibrinolytic agents, catheter-based treatment, or surgical embolectomy. Most patients with low-risk PE (normal vital signs and normal serum troponin, brain natriuretic peptide, and normal echocardiography) are treated successfully with standard anticoagulation, and many can be treated as outpatients. In contrast, patients with high-risk PE (systolic blood pressure < 90 mm Hg and no contraindications) often benefit from escalated treatment. Treatment decisions for patients with moderate-risk PE (normotension with evidence of right ventricular damage or dysfunction) are most controversial. Most patients in this category of risk recover with standard therapy, but some benefit from escalated treatment. Patients with cancer with an incidentally discovered PE should be risk stratified the same as those who have clinically suspected PE.