Study Design: Retrospective case series. Objective: We present a minimally invasive spinopelvic fixation technique for unstable bilateral sacral fractures and describe a technical report. Summary of Background Data: Unstable sacral fractures are severe injuries with high mortality and morbidity due to pain and malunion. Galveston technique is useful for rigid fixation of an unstable sacral fracture. However, wound-related complications with this technique have been relatively common because of extensive contusion of the skin or poor blood supply after embolization. Materials and Methods: There were 34 patients with unstable pelvic fractures between 2005 and 2012. We performed conventional open surgery between 2005 and 2009. Minimally invasive spinopelvic fixation was performed between 2009 and 2012. Minimally invasive technique needs 4 small, lateral incisions for percutaneous lumbar pedicle screw insertion. We pushed a pure titanium rod into the paravertebral muscle. Results: The average surgical time was 345 minutes in the conventional fixation and 208 minutes with the minimally invasive fixation. The average intraoperative bleeding was 520mL in the conventional fixation and 290mL in minimally invasive fixation. When comparing deep wound infection, 3 of 8 (38%) patients who received conventional fixation had methicillin-resistant Staphylococcus aureus infections, whereas nobody who received the minimally invasive fixation acquired infection. Bony union was achieved in 15 of the 16 patients. Conclusions: In this study, minimally invasive spinopelvic fixation required a shorter surgical time, incurred less bleeding, and had a lower infection rate than fixation with the conventional Galveston technique.