- Background: To demonstrate how to perform successful REBOA/ABO in extreme elderly patient - Materials and methods: A case report - Results: A 86-year old male, he was struck by car and transferred to Level I Trauma center at Siriraj hospital after injury for 30 minutes. Arrival clinical signs were coma and hypotension, lowest SBP was 50 mmHg. Primary survey found unstable pelvic fracture and severe head injury. We did REBOA at Zone I via left common femoral artery which aim to do partial balloon technique by inflation with 15-18 mL and arterial line monitoring for goal SBP around 100-120 mmHg due to his extreme age and associated traumatic brain injury. After CT scan showed no intra-abdominal injury, we did reposition the balloon to zone III under fluoroscopy. Unexpectedly, during deflation the balloon before removal, we found fresh blood through the balloon port, then ruptured balloon was suspected and confirmed with aortography. We immediately converted to remove by open technique due to balloon was failed to shrinkage through 7-Fr sheath. We reviewed the CT scan was shown calcified plaque along aorta and arteries which could be the cause of ruptured balloon. Throughout all procedures to stop bleeding which are pelvic external fixation, preperitoneal pelvic packing and embolization at right internal iliac artery, patient was given PRC only 4 units and no inotropic support to stabilizing patient. Total inflation time was 167 minutes with partial and intermittent REBOA technique. ICU Admission lab showed normal renal and liver function. - Conclusion : To perform ABO/REBOA in extreme elderly trauma patient, the partial balloon technique with goal SBP to balance between associated injury in polytrauma patient is very essential. The specific concern in this group would be related with reserve function and the changing of vascular access. Techniques for detection and solving the uneventful conditions should be prepared and learnt to successfully save the elderly patient.