From January 1993 to March 1995, 162 patients with osteosarcoma of extremities were treated according to the IOR/OS-4 protocol. 133 patients had localised disease, while 29 had metastases at diagnosis. These last patients were simultaneously operated upon for their primary and metastatic lesions. Chemotherapy consisted preoperatively of two cycles of high dose methotrexate (HDMTX) and one cycle each of cisplatin (CDP)-doxorubicin (ADM), CDP/ifosfamide (IFO) and IFO/ADM. After surgery, patients were treated with the aforementioned drugs used as single agents. The mean follow-up of all patients was 6.5 years (5.5-8 years). Surgery was a limb salvage in 94% of cases, and the 5-year event-free survival (EFS) and overall survival (OS) rates were 56 and 71% for patients with localised disease, and 17 and 24% for patients with metastases at diagnosis. These results did not differ from those achieved in our previous study (IOR/OS-3) in which IFO was used only postoperatively in poor responders.