report the evidence of regression of multiple metastases following non-myeloablative stem cell transplantation (NST) from an HLA-identical sibling in a case of relapsed fibroblastic osteosarcoma. The course of NST was well tolerated. Full donor chimerism was achieved on day +150 both for CD15+ and CD3+ cells. Complete remission was achieved on day +116. On day +210 the patient relapsed with a scapular metastasis that was unresponsive to four doses of donor lymphocyte infusion (DLIs). To our knowledge, this is the first reported case showing the achievement of complete remission following NST in an osteosarcoma patient.