It has been reported that bone marrow cells (BMCs) differentiate into endothelial cells of blood vessels, and that granulocyte colony-stimulating factor (G-CSF) mobilizes progenitors in the BMCs to the peripheral blood, while macrophage colony-stimulating factor (M-CSF) augments the production of monocytes. We examined whether M-CSF augments the differentiation of BMCs into endothelial cells of blood vessels using a hindlimb-ischemic model. Either G-CSF or M-CSF, or both, was administered to the hindlimb-ischemic mice for 3 days. Both M-CSF and G-CSF augmented the differentiation of BMCs into endothelial cells of blood vessels through vascular endothelial cell growth factor (VEGF), resulting in early recovery of blood flow in the ischemic limbs.