BackgroundThere is a paucity of data regarding the prevalence of preoperative deep vein thrombosis (DVT) in patients with long bone (including femur, tibia and fibula) fractures of the lower limbs. We performed a meta-analysis to address the issue.MethodsElectronic databases, including PubMed, EMBASE, the Web of Science, the Cochrane Library, the VIP database, CNKI, and the Wanfang database, were systematic searched for original articles that reported the prevalence of preoperative DVT in long bone fractures of the lower limbs from January 2016 to September 2021. The prevalence of preoperative DVT was pooled using random-effects models, and subgroups were established according to study type, detection method, sample size and fracture site.ResultsTwenty-three articles reporting on 18,119 patients were eligible. The overall pooled preoperative DVT prevalence was 24.1% (95% CI 19.3–28.8%). In different subgroups, the preoperative DVT prevalences were 18.2–27.3%, 15.2–28.6%, 23.1–24.9%, 18.2–26.0% and 23.2–23.4% for different study designs, sample sizes, age groups, detection methods and fracture sites, respectively.ConclusionsDespite the heterogeneity among studies, this systematic review suggests that the prevalence of preoperative DVT, which may seriously affect the prognosis of patients, is high. Therefore, greater efforts should be devoted to the improvement of screening and prevention strategies for preoperative DVT in lower-extremity long bone fractures.Level of Evidence:Level III.Trial RegistrationThe study was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database with the registration number CRD42022324706.