Allogeneic hematopoietic stem cell transplantation is an effective treatment for hematological malignancies. Peripheral blood stem cells (PBSCs) are increasingly used as an alternative to bone marrow for allogeneic transplantation. However, predictive factors for the response to recombinant human granulocyte stimulating factor (rHuG-CSF) in healthy donors have not been extensively studied. We analyzed the side effects, laboratory test results after administration of rHuG-CSF and the factors influencing mobilization of peripheral blood stem cells in 30 healthy donors. Bone pain, fever and headache were observed with high frequency after administration of rHuG-CSF. WBCs and reticulocytes increased, and RBCs and platelets decreased significantly after administration rHuG-CSF. Biochemical examination revealed significant elevations of LDH, CRP, ALP and UA. Univariate analysis showed the age of donors (< 50 vs. > 50, p = 0.041) and the lymphocyte counts before administration of rHuG-CSF (p = 0.032) to be correlated with the number of CD34 positive cells. From a multivariate analysis, the tendency for good mobilization with a twice daily dose of rHuG-CSF (p = 0.065) was observed. The rHuG-CSF schedule may be the most important factor affecting peripheral blood stem cell mobilization and collection in healthy donors.