The standard method for treating posterior pelvic ring injuries involves sacroiliac joint cannulated lag screw fixation, necessitating repeated fluoroscopy and leading to radiation exposure. The O-arm navigation system, designed for spine screw fixation, is applied in pelvic injuries to enhance precision. A successful case involved a 39-year-old male with a complex pelvic injury, where sacroiliac screw fixation was performed in the prone position using the O-arm guide. The patient, injured at a construction site, showed fractures and widening of the symphysis pubis and right sacroiliac joint. Surgery was planned for both lumbar and pelvic regions due to an L3 burst fracture. The O-arm system demonstrated efficacy in precise screw placement, reducing surgical duration, and minimizing complications. The discussion emphasizes early pelvic fixation benefits, with percutaneous iliosacral screws standing out. Conventional fluoroscopy-guided methods pose challenges, and the O-arm system proves advantageous, especially for less experienced surgeons. Future advancements may enable pelvic surgery using the O-arm without C-arm guidance if instrumentation for pelvis fixation is developed.