Background <p>Pelvic fractures and iliac vessel injuries share an anatomical relationship because of the proximity of the vessels to the bony pelvis. This study aimed to evaluate the impact of concomitant pelvic fractures on clinical outcomes in patients with iliac vessel injuries.</p> Methods <p>We performed a retrospective cohort study using secondary analysis of the 2017 National Trauma Data Bank Research Dataset. Adult patients (≥ 18 years old) with iliac vessel injuries were identified using ICD codes and stratified by the presence of pelvic fractures. Demographics, injury patterns, complications, and outcomes including mortality, length of hospital stay, and complications were compared. Multivariate logistic regression identified factors associated with mortality after adjusting for age, sex, race, injury severity score (ISS), abbreviated injury scale (AIS) scores, and comorbidities.</p> Results <p>Among the 1,127 patients with iliac vessel injuries, 235 (20.9%) had concomitant pelvic fractures. Patients with pelvic fractures had similar demographics, but more associated abdominal trauma (60.0% vs. 48.4%, <i>p</i> = 0.002) and lumbar spine fractures (24.7% vs. 18.0%, <i>p</i> = 0.022). Although overall mortality rates were similar (17.9% vs. 20.6%, <i>p</i> = 0.348), these groups demonstrated distinct injury patterns that warrant different clinical considerations. ICU length of stay (median 5 days in both groups, <i>p</i> = 0.193) and overall complications (38.3% vs. 36.9%, <i>p</i> = 0.690) were comparable between groups. In multivariate analysis, pelvic fractures were not independently associated with mortality (OR 0.820, 95% CI 0.499–1.350, <i>p</i> = 0.436) after adjusting for age, injury severity, and physiologic parameters.</p> Conclusions <p>The presence of pelvic fractures was not independently associated with mortality in adjusted analysis.</p>