The aim of this nonrandomized controlled study (level 3)was to evaluate whether preoperative denosumab treatment can reduce intraoperative blood loss, facilitate surgical treatment, and improve local control of sacral giant-cell tumor (GCT).Surgical treatment of sacral GCT is very difficult due to extensive bone destruction and complex anatomical structures. The huge intraoperative blood loss may interrupt surgical management and judgment of tumor range. Denosumab can inhibit the differentiation of osteoclast-like giant cells and bone destruction by blocking RANKL-RANK pathway.Study group (preoperative denosumab treatment) and control group (no denosumab treatment) were matched for age, gender, tumor site, staging, and tumor size. In study group, enhanced computed tomography (CT) was performed before and after denosumab treatment. The comparison parameters between 2 groups: CT enhancement rate, intraoperative blood loss, and oncologic outcome.The mean preoperative time of denosumab treatment was 5.2 months in study group. The mean CT enhancement rate of study group was 2.60 before treatment and 1.37 after treatment (P = .012). The posttreatment CT enhancement rate of study group was significantly lower than that of control group (P = .007). The mean intraoperative bleeding of study group and control group was 2166.7 and 5240 mL, respectively (P = .040). The mean operative time of study group and control group was 268.3 and 268.5 minutes, respectively (P = .997). The recurrence rate of study group (66.7%) was significantly higher than that of control group (0%) (P = .046).Preoperative denosumab treatment has the tendency to reduce blood supply and intraoperative bleeding of sacral GCT. But the sclerosis and bony separation can increase the difficulty of tumor curettage and lead to high recurrence rate after denosumab treatment. It is necessary to study the best surgical opportunity after denosumab treatment and precise method to judge tumor range.