In order to better evaluate the role of bone marrow purging procedures in the treatment of stage IV neuroblastoma, two similar groups of patients, prospectively treated during the same period at Léon Bérard Center, Lyon, France, and at Giannina Gaslini Institute, Genova, Italy, were reviewed. 18 children were treated in Lyon with a protocol including induction chemotherapy, surgery and a single course of high-dose chemotherapy followed by purged autologous bone marrow rescue. 21 patients were treated in Genoa with a very similar protocol which did not include purging procedures. Progression-free survival at 6 years was 12% (95% confidence interval 0-24%), without any difference between the two series of patients. The only prognostic factor for long-term survival was the persistence (or not) of bone lesions and the presence of metastatic disease (bone or bone marrow) at graft. The small numbers in the two groups and the very poor outcome make it difficult to conclude on the efficacy of purging.