OBJECTIVE: The purpose of this study was to describe a blinded intra-aortic balloon occlusion (IABO) procedure in pelvic fractures (PF) for patients with critically uncontrollable hemorrhagic shock (CUHS). METHODS: Of 2,064 patients treated for PF, 13 underwent IABO during initial resuscitation to control massive pelvic bleeding leading to CUHS. Our IABO procedure consists of internal aortic occlusion without fluoroscopy, using a latex balloon inflated in the infrarenal aorta. Retrospectively collected data included demographics, fracture classification, additional injuries, blood transfusions, surgical interventions, angiographic procedure, physiologic parameters, and survival. RESULTS: All balloons were successfully placed, and a significant increase in systolic blood pressure (70 mm Hg, p = 0.001) was observed immediately after IABO. Twelve of 13 patients became transferrable. Angiography performed after IABO was positive for arterial injury in 92% of patients, and 9 patients benefitted from arterial embolization. Survival rate was 46% (6 of 13) and was inversely related to the length of inflation (p = 0.026) and the mean Injury Severity Score (p = 0.011). CONCLUSION: This IABO procedure can be life saving in the management of patients with CUHS from PF, permitting transport to angiography. However, the decision for such treatment must be as quickly as possible after trauma to reduce the time of occlusion.