To describe the outcomes of a large number of patients with pelvic osteosarcoma, and to define the guidelines for appropriate treatment.We reviewed 60 consecutive patients with primary pelvic high-grade osteosarcoma. The tumour involved the whole hemipelvis in 15 cases, while the most common location was the iliac wing in 29 cases (48.3%): 25 of these adjacent to or passing the sacroiliac joint.Thirty patients underwent surgery; there were 16 hindquarter amputations and 14 internal hemipelvectomies. All the patients who presented with metastasis died of their disease. In 18 cases wide margins were achieved, however, eight patients experienced local recurrence. Of the series, only eight patients are still alive.The use of intense chemotherapy and surgical wide margin, hardly seems to achieve local control, however, tumour necrosis was correlated with positive prognosis. When internal hemipelvectomy it is not safe enough, amputation must be considered, particularly for cases with sacrifice of the sciatic nerve roots or for older patients where a shorter surgical procedure can be less risky.