Recently, high-dose therapy has been evaluated in patients with multiple myeloma, mainly with autologous transplant support. As a result of rapid hemopoietic engraftment with peripheral blood stem cells collected after chemotherapy and/or hemopoietic growth factor priming, procedure-related mortality has dropped to below 5%. When applied within 12 months from initial therapy, autologous transplants effect complete remissions in up to 50% of patients, with median event-free and overall survival durations on the order of 2.5 and 4 to 5 years, respectively. Complete response rates with allogeneic transplantation range from 30% to 50%, and procedure-related mortality is approximately 40%. Although the median durations of event-free and overall survival are shorter with allogeneic transplants, approximately 35% to 40% of patients survive with minimal disease for at least 5 to 6 years. Direct comparisons of standard therapy and autologous transplants have just begun.