Aim: To investigate whether the prophylactic local delivery of mobilized periph-eral blood mononuclear cells (M-PBMNC) could prevent peripheral microangio-pathy in diabetic nude mice. Methods: Diabetic nude mice were induced with intraperitoneal injections of streptozotocin. With the time course of diabetes, we detected the capillary and arteriole density of mice adductor muscles by immuno-histopathy. In situ apoptosis was detected by using TdT-mediated dUTP nick end labeling (TUNEL) methods. M-PBMNC were labeled and locally delivered to the adductor muscles. Mononuclear cells were also isolated and cultured in vitro for the detection and counting of endothelial progenitor cells(EPC). Results: Rarefication of capillaries and arterioles, enhanced apoptosis in adductor muscles,and reduced circulating EPC in diabetic nude mice. Prophylactic local delivery of M-PBMNC halted the progression of microvascular rarefaction in hind-limb skel-etal muscles by inhibiting apoptosis. We detected the survival, migration and incorporation of transplanted M-PBMNC into the murine vasculature in vivo. In addition, more EPC were available from M-PBMNC than non-mobilized cells.Conclusion: These results suggested that the prophylactic local delivery of M-PBMNC may represent a novel approach for the treatment of microvascular complications in diabetics.