A retrospective investigation of sacral giant cell tumors of the bone (GCTB) was conducted. For a study, researchers sought to determine if an ultra-short course of neo-adjuvant denosumab treatment for sacral GCTB might result in a radiological and histological response. Make nerve-saving surgery easier? Were oncological and functional outcomes satisfactory? About 66 patients with sacral GCTB who had neoadjuvant denosumab and nerve-sparing surgery were split into 2 groups: ultra-short course (≤3 doses and operation within D21 since first dose, 41 patients) and conventional (>3 doses and operation after D21 since first dose, 25 patients). Oncological and functional results, as well as radiological and histological responses, were compared. The ultra-short course group received fewer denosumab doses (2.1 vs. 4.8, P<0.001) and had a shorter time to surgery (12.2 days vs. 72.3 days, P<0.001). The 2 groups had similar radiological and histological responses, with the ultra-short course group having less fibrosis and ossification. The operational time (199.9 minutes vs 187.8 minutes, P=0.364) and blood loss (1,552.4 mL vs 1,474.0 mL, P=0.740) were similar. The majority of the patients (94.8%) got adjuvant denosumab. In 3 cases (8.8%) and 5 cases (20.8%) of each group had a local recurrence after a mean follow-up of 29.4 months (P=0.255). The functional status [Motor-Urination-Defecation scores: 25.9 vs 25.7, P=0.762] and estimated recurrence-free survival (56.2 vs 51.2 months, P=0.210) differed between the 2 groups. For sacral GCTB, an ultra-short course of neo-adjuvant denosumab could elicit the same radiological and histological responses as a typical term. The lower degree of fibrosis and ossification might make nerve-sparing surgery easier and result in better local control and function.