There are a number of studies dealing with intensive chemotherapy and stem cell transplantation in multiple myeloma. As to autologous transplantation best results have been obtained with younger patients (below 60 years) who had responsive disease and received their transplant within one year after start of treatment. Unfavourable prognostic factors were a high beta 2-microglobulin level and abnormal cytogenetics including any translocation or chromosome 11/13 abnormalities. Only one phase III study has been published, indicating a favourable effect of autologous transplantation. Despite the existence of a so-called 'graft-versus-myeloma effect' the overall outcome of patients after allogeneic transplantation is not better than after autologous transplantation, probably due to the inclusion in the published studies of heavily pretreated and refractory patients responsible for a high treatment related mortality. The ultimate value of intensive treatment of multiple myeloma will become clear in the coming years when more data become available from current phase III studies including the Dutch HOVON multicentre trial in which conventional treatment is compared with intensified therapy including bone marrow ablation and autologous stem cell transplantation.