Fifty-five patients with advanced multiple myeloma received purified CD34-selected peripheral blood progenitor cell transplants following myeloablative chemotherapy. A median of 4.1 x 10(6) CD34 cells/kg (range 1.2-30.7) were infused after busulfan (14 mg/kg) and cyclophosphamide (120 mg/kg); granulocyte-macrophage colony-stimulating factor was used until hematopoietic recovery. Median time to neutrophils >0.5 x 10(9)/l and platelets >20 x 10(9)/l were 12 days (range 10-16 and 8-184 days, respectively). Median follow-up of survivors from the time of transplantation is 33 months (range 7 to 44 months). Thirty-one patients are alive, 19 progression-free. Median progression-free survival is 14 months. Actuarial 3-year progression-free and overall survival are 29+/-14% and 47+/-17%. CD34-selection of peripheral blood progenitor cells provides effective hematopoietic support with significant progression-free and overall survival.