The value of early myeloablative therapy supported by autologous bone marrow or blood progenitor cells was assessed in 72 patients with multiple myeloma who were treated within 1 year of initial therapy. Forty-five patients were consolidated during remission, and 27 patients were treated for primary refractory disease. Outcomes were compared with those of similar patients who did not receive intensive treatment primarily for socioeconomic reasons. Among patients who had responded previously, myeloablative therapy increased the rate of complete remission from 5% to 45% (P < .01) but did not prolong progression-free intervals or survival times. The same treatment controlled the myeloma in 70% of patients with primary resistant disease and prolonged the median survival from 37 to 83 months (P = .03). Intensive treatment for primary resistant myeloma administered later in the disease course resulted in significantly lower response rates and shorter progression- free intervals. Current myeloablative regimens supported by autologous stem cells appeared useful primarily in patients with primary resistant disease during the first year of therapy.