The incidence of venous thromboembolism after major trauma has been estimated to be as high as 60%, despite appropriate prophylaxis. Pulmonary embolism is associated with deep venous thrombosis and also with significant rates of morbidity and mortality. This study examined risk factors for pulmonary embolism among patients with pelvic and lower-extremity fractures in the National Trauma Data Bank. Univariate analysis and multiple logistic regression were used to assess potential risk factors for pulmonary embolism during the index hospitalization period. A total of 199,952 patients with pelvic and lower- extremity fracture were identified. Of these patients, 918 (0.46%) had a pulmonary embolism and 117 (12%) of them died during hospitalization. The risk of pulmonary embolism was significantly increased in patients with multiple fractures (odds ratio, 1.89; P<.001) only. No significant relationship was found with fracture location (pelvis, femur, tibia). Other factors that were associated with increased rates of pulmonary embolism were obesity (body mass index >40 odds ratio, 3.38; P<.001), history of warfarin use (P=.009), hospital disposition (surgery odds ratio, 1.68; P<.001; intensive care unit odds ratio, 2.4; P<.001), and hospital setting (university odds ratio, 1.36; P<.001). Multiple pelvic or lower-extremity fractures, but not their anatomic locations, were associated with pulmonary embolism in the National Trauma Data Bank. As expected, obese patients and those with a history of warfarin therapy have higher rates of pulmonary embolism. This study offers guidance in identifying patients with musculoskeletal trauma who are at elevated risk for pulmonary embolism.