Hematologic effects of granulocyte colony-stimulating factor (G-CSF) and erythropoietin (EPO) combination after printing intensive chemotherapy in the treatment of female breast carcinoma are presented. In a previous group treated with G-CSF alone, 36% of patients became anemic and had to be transfused for correction of their anemia. To the present study 11 consecutive patients with different stages of breast carcinoma were admitted. All were given priming intensive chemotherapy (epirubicin 150 mg/m2 and cyclophosphamide 1300 mg/m2 followed by subcutaneous application of G-CSF at a dose of 5 micrograms/kg/day and EPO 250 IU/kg/day. In cases where leucocyte counts dropped below 1 x 10(9)/l and hemoglobin levels fell to 85 g/l administration of growth factors was started. The therapy stopped when normal leucocyte count reached 4 x 10(9)/l for G-CSF and hemoglobin level rose to 115 g/l for EPO. Our results show significant difference between MNC/T1 (min.), CD34+ cells/microliters (min.), CFU-GM/ml (min.), BFU-E/ml (min.) and MNC/microliters (max.), CD34+ cells/microliters (max.), CFU-GM/ml (max.), BFU-E/ml (max.) p < 0.01, with mean peak values of 16.9-fold for circulating MNC/microliters, 7.8-fold for CD34+ cells/microliters 23.4-fold for CFU-GM/ml and 28.7-fold increase for BFU-E/ml. Side effects were minimal, no infectious complications occurred, body temperature did not rise over 38 degrees C and no corrections of anemia were needed. It is concluded that the administration of G-CSF plus EPO combination following intensive chemotherapy reduces hematologic toxicity and induces large amount of hemopoietic progenitors suitable for autologous transplantation in women with breast carcinoma.