Explore the validity of the Caprini Score in orthopaedic patients with lower-extremity fractures.Retrospective cohort study.Level I trauma academic medical center.Eight hundred forty-eight patients with lower-extremity fractures from 2002 to 2015 with exclusion criteria: minors, follow-up less than 30 days.Stratify patients into 2 groups: high-risk (pelvic and acetabular fractures) and low-risk groups (isolated foot and ankle fractures).Caprini Score, fracture classification, length of follow-up, deep vein thrombosis (DVT) chemoprophylaxis, and venothromboembolism (VTE) events [DVT and/or pulmonary embolism (PE)] diagnosed with objective testing.Eight hundred forty-eight patients (499 M; 349 F) 18-93 years of age (average 43.7) with average body mass index of 29. Three hundred high-risk and 548 low-risk patients with no differences in demographics with average follow-up of 288 days. There were 33 (3.9%) VTE events, which were more common in the high-risk group (8%: 9 DVT, 15 PE) than the low-risk group (1.6%: 8 DVT, 1 PE) (P < 0.0001). The cutoff that best-predicted VTE events based on receiver-operating curves was 12 (c = 0.74) in the high-risk group, 11 (c = 0.79) in the low-risk group, and 12 (c = 0.83) overall.There was a significant lower VTE rate found in the low-risk group, but the Caprini prediction model was not significantly different between the 2 groups. This displays that patient factors play a large role in the development of VTE events independent of injury type. The Caprini score may help identify patients who may require increased protection.Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.