Data regarding effects of cholesterol levels on hematopoietic stem cell mobilization are limited. We retrospectively reviewed the relationship between serum total cholesterol levels and peripheral blood CD34 (PBCD34) cell counts in 52 granulocyte colony stimulating factor (G-CSF) induced mobilization cycles with or without chemotherapy. The cholesterol levels between the poor and good mobilization groups (median 172 mg/dl vs. 183.5 mg/dl, respectively, p = 0.18) were not different. No significant correlation was obtained between the cholesterol levels and PBCD34 counts (r = 0.02, p = 0.85). No significant correlation was obtained between cholesterol levels and PBCD34 counts in patients neither mobilized with G-CSF alone (r = 0.02, p = 0.9) nor G-CSF plus chemotherapy (r = 0.04, p = 0.8). The results of the study indicate that there was no effect of cholesterol on hematopoietic stem cell mobilization. Prospective cohort studies are needed to demonstrate the effect of cholesterol on mobilization and its extent in humans. (C) 2012 Elsevier Ltd. All rights reserved.