To explore the efficacy and safety of high-dose of etoposide with granulocyte colony-stimulating factor (G-CSF) for mobilization of peripheral blood stem cells, 10 patients with hematologic malignancies including 6 patients with multiple myeloma and 4 with non Hodgkin' s lymphoma received an etoposide dose of 1.6 g/m2. The total dose of undiluted etoposide was given on day 1 as a continuous intravenous infusion via a central vein for 10 hours. G-CSF 5 microg/kg was used on day 3 and given daily subcutaneously until leukopheresis was completed. The results showed that leukopheresis was started at days 11 (range 9-13 days) following etoposide therapy, the mean number of CD34+ cells collected in all 10 patients was 9.4 x 10(6)/kg (range 4.2 - 17.3 x 10(6)/kg), by an average of 2.6 leukophereses (range 1-4) times. Mobilization procedure that produced yields of greater than 4.0 x 10(6)/kg were achieved in every patient. Toxicity showed oropharyngeal mucositis, faucitis and urethritis respectively in 3 patients. It is concluded that high-dose etoposide with G-CSF is an effective and safe mobilizing regimen for autologous peripheral blood stem progenitor cells in patients with hematologic malignancies.