Long term outcome and prognosis factors of patients with metastatic osteosarcoma were evaluated on 29 observations from 3 centres reviewed retrospectively. Twenty-nine patients less than 18 years old were treated from 1990 to 1998. Only 29 of these patients had received similar treatments associating chemotherapy and surgery, adapted according to histological and clinical response to treatment, as recommended by the SFOP. Overall survival at five years was 26%, and disease free survival 14%. Eight patients are alive, four in first complete remission (CR) and four in second CR. Three of the four patients alive in first CR had bone metastases at diagnosis. On univariate analysis, factors predicting survival are: the numbers of organs affected by metastatic lesions, the number of lung nodules and the type of surgery. This is, to our knowledge, the first report of long term survivors with bone metastases at diagnosis. Metastatic osteosarcoma prognosis remain poor. A randomised study would help to define the best possible treatment for this disease.