Eighteen patients with high grade malignant fibrous histiocytoma (MFH) of bone and 112 patients with high grade osteosarcoma (OS) of the extremity were treated with neoadjuvant chemotherapy comprised of methotrexate, cisplatinum, doxorubicin and ifosfamide. For the 18 patients with MFH, surgery involved amputation in 2 cases and limb salvage in 16 (89%); the 112 osteosarcoma patients had amputation in 8 cases and limb salvage procedure in 104 cases (93%). The rate of good histologic response to preoperative chemotherapy (90% or more tumor necrosis) was significantly higher in patients with osteosarcoma than in patients with MFH (74% vs 28%; p < 0.003). However, at a median follow-up of 38 months (range 25-61), the 3-year event-free survival (EFS) did not differ in the two groups (MFH 77.8%, OS 70.5%; p = ns). In patients with MFH, no local recurrences were registered, whereas in the osteosarcoma group there were 6 local relapses (5.%). The effectiveness of neoadjuvant chemotherapy in the treatment of osteosarcoma has been assessed during the last 15 years. The results of the present study seem to indicate that, in spite of a usually poor histologic response to preoperative treatment, neoadjuvant chemotherapy is very effective also in MFH of bone.