Anemia is a universal finding in patients undergoing autologous bone marrow transplantation (BMT). Effective therapies to increase the number of autologous red blood cells could result in a lower morbidity and mortality associated with red blood cell transfusions. We examined whether the addition of erythropoietin (Epo) to intensive therapy supported by progenitor cell transplantation and granulocyte colony- stimulating factor (G-CSF) would result in a lower requirement for red blood cell transfusions. Thirty-five patients with lymphoma were randomized to receive Epo versus placebo. Epo (600 U/kg three times per week) or placebo was begun 3 weeks before administration of high-dose therapy. Epo was held during the week of the preparatory regimen, and restarted on the day after BMT. All patients also received G-CSF following BMT. No significant differences were noted between the two groups in terms of patient characteristics at pretreatment or post-BMT evaluation. There were no differences in the total number of red blood cell units transfused (median Epo: 8 v placebo: 6, P = .22) nor the number of platelet transfusions given (median Epo: 12 v placebo 5, P = .14). Engraftment of granulocytes (absolute neutrophil count > or = 500/microL) occurred in a median of 12 days (range, 9 to 33) for the patients receiving Epo and G-CSF, compared with a median of 10 days (range, 8 to 22) for those receiving placebo and G-CSF (P = .70). Likewise, there were no differences in the time to platelet count > or = 20,000/microL without further transfusions with a median of 22 days (range, 15 to 150+) for those receiving Epo and G-CSF compared with a median of 20 days (range, 11 to 54) for those patients receiving placebo and G-CSF (P = .28). The combination of G-CSF and Epo as administered in this study appears to be safe but does not result in an improvement in the total number of red blood cell transfusions or total number of single donor platelet units transfused.