Seventy-two patients with a localized osteosarcoma were treated between September 1979 and December 1987 by neoadjuvant chemotherapy, local surgery and post-operative chemotherapy. Chemotherapy regimens varied throughout the years but always comprised high dose methotrexate with leucovorin rescue and adriamycin pre-operatively for children under the age of 15, and ifosfamid and cis platinum in adults. Post-operative chemotherapy for bad responders (greater than 10% of residual malignant cells), was at first an association of adriamycin and cis platinum, and later of holoxan and cis platinum. Surgery changed from amputation to local conservative surgery (graft or prosthesis) which is now the most frequent surgery--61% of the patients are alive and disease-free at 5 years. Good responders to pre-operative chemotherapy have a much better prognosis (81% at 5 years) than bad responders (45%). There is no significant difference according to age or pre-operative chemotherapy regimen.