According to the published report on current practice of hematopoietic SCT in Europe, high-dose therapy (HDT) with autologous stem cell support is a standard of care in paediatric patients with high risk (HR) or relapsed Ewing's sarcoma (ES). Randomized trials, however, have not confirmed the value of this procedure yet. In this retrospective analysis we intended to evaluate the role of HDT as a consolidation therapy in first remission of ES. A total of 102 patients were included in the analysis and divided according to the following risk factors: metastatic disease at presentation, feasibility of surgery and histological response after induction. Forty-one patients were classified as standard risk (SR) patients, while the remaining 61 children, with at least one risk factor, were classified as HR patients. HR group patients were non-randomized and qualified according to the decision of the local clinician to give a conventional consolidation (CC) or to perform high-dose chemotherapy and radiotherapy in selected patients. Twenty-six children were given CC while 35 patients were treated with HDT. The HDT consisted of oral BU 4 mg/kg p.o. in divided doses daily for 4 days (total dose 16 mg/kg) followed by melphalan 140 mg/m(2) i.v. on day -2. Probability of relapse-free survival (RFS) in median observation time was significantly worse in HR patients who were given CC therapy as compared with children with HR features receiving high-dose chemotherapy (0.27 vs 0.66 (P = 0.008); OS 0.31 vs 0.71 (P = 0.007), respectively). Patients from the SR group had a probability of RFS of 0.72 and OS of 0.75, and the difference between SR and HR patients after HDT was NS (P = 0.37). Our observation confirms that the consolidation of the first-line treatment with BU and melphalan improves the outcome in ES patients with HR features.