Objectives:To assess the incidence, risk factors, and clinical outcomes of Ogilvie syndrome (OS) in patients with pelvic and/or acetabular fractures.Design:Retrospective cohort study.Setting:Level 1 trauma center.Patients:One thousand sixty patients with pelvic and/or acetabular fractures treated at Rigshospitalet, Copenhagen, between 2009 and 2020.Intervention:Interventions comprised the treatment of pelvic and/or acetabular fractures with emergency external and/or internal fixation.Main Outcome Measurements:Outcomes included diagnosis of OS, perioperative complications, ICU stay and length, length of admission, and mortality.Results:We identified 1060 patients with pelvic and/or acetabular fractures. Of these, 25 patients were diagnosed with OS perioperatively, corresponding to incidences of 1.6%, 2.7%, and 2.6% for acetabular, pelvic, and combined fractures, respectively. Risk factors included congestive heart failure, diabetes, concomitant traumatic lesions, head trauma, fractures of the cranial vault and/or basal skull, retroperitoneal hematomas and spinal cord injuries, and emergency internal fixation and extraperitoneal packing. Six (24%) patients underwent laparotomy, and all patients had ischemia or perforation of the cecum for which right hemicolectomy was performed. Ogilvie syndrome was associated with a significant increase in nosocomial infections, sepsis, pulmonary embolism, ICU stay, and prolonged hospital admission.Conclusion:Ogilvie syndrome in patients with pelvic and/or acetabular fractures is associated with increased risk of perioperative complications and prolonged hospital and ICU stays, resulting in an increased risk of morbidity and mortality.Level of Evidence:Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.