We present a case of a 44-year-old woman with an unusual location of a brown tumor in the sacral vertebrae due to parathyroid adenoma. She was admitted to our clinic with the complaint of low-back pain and was later diagnosed to have a brown tumor. The patient underwent surgery and partial sacrectomy and iliac wing resection was performed in Orthopedic Surgery Department. Subsequently the patient underwent parathyroid adenoma excision in General Surgery Department. On her control examination at postoperative 3 months, she had no pain and was able to perform daily activities without any problem. We believe it is an interesting clinical case both because it shows a very rare localization of brown tumor and points out the importance of employing a wide clinical scope in the differential diagnosis of back pain.