Insufficiency fractures of the sacrum are relatively common and cause severe low back and buttock pain. Percutaneous vertebroplasty is effective for treating vertebral compression fractures. We present a case of percutaneous sacroplasty for the treatment of low back and buttock pain in a sacral insufficiency fracture. A 79-year-old male with non-small lung cancer presented with severe low back and buttock pain after series of radiation treatments. Preoperative MRI showed both a sacral ala and S2 metastatic insufficiency fracture. An epidural port was inserted for continuous morphine infusion and sacral nerve root blocks were performed. However, his pain did not diminish and we attempted percutaneous sacroplasty. Both sides of the sacroplasty were done with a fluoroscopy-guided technique with 1.7 ml and 2.3 ml of bone cement injected into the right and left sacral ala. Pain relief was significant and the patient was able to sit down 1 day after the procedure.