We evaluated the long-term results obtained in 402 patients with non-metastatic Ewing's sarcoma (ES) of the bone treated in a single institution with adjuvant and neoadjuvant chemotherapies between 1972 and 1992. Multivariate analyses showed male gender, age older than 14 years, high serum lactate dehydrogenase (LDH) level, axial location of the tumour, use of radiotherapy alone as a local treatment, and poor histological response to chemotherapy, to be independent, adverse prognostic factors for event-free survival (EFS). At a mean follow-up of about 18 years (10-30 years), 177 patients (44.0%) remained continuously free of disease, 2 died of doxorubicin-induced cardiotoxicity and 8 developed a second neoplasm (5 died, and 3 are alive and free of disease). 215 patients relapsed with metastases and/or local recurrence: 14 are alive and free of disease, 1 is alive with uncontrolled disease, and 200 died. The overall survival (OS) at real follow-ups of 5-, 10-, 15- and 20-years was 57.2, 49.3, 44.9 and 38.4%, respectively. We conclude that since local or systemic relapses, treatment-complications and second malignancies are more common after 5 years or more from the beginning of treatment; a long-term follow-up is mandatory for patients with ES.