In a 1-year retrospective review, 30 pulmonary emboli were diagnosed among 1,316 trauma patients who survived for at least 24 hours after admission to a Level I trauma center. Pelvic fractures, age over 55 years, severe single or multiple system trauma, and cannulation of central veins all appear to place injured patients at increased risk. Long bone fractures were not associated with an increased risk. The majority of pulmonary emboli were diagnosed during the first week of hospitalization with some as early as 24 hours and none later than 15 days postinjury. Although the etiology of these early emboli is uncertain, prolonged immobilization does not appear to play a role in placing these patients at increased risk for thromboembolic events. Pulmonary embolism should be suspected in any injured patient with respiratory compromise, and an aggressive approach to diagnosis is warranted.