Endothelial progenitor cells (EPCs) constitute a promising focus for research in regenerative medicine. These cells originate from the bone marrow and other circulating hematopoietic cells and regulate tissue regeneration and vascular integrity. EPC mobilization serves for neovascularization and re-endothelialization after injury in multiple organ systems, including the renal and cardiovascular systems. Both their number and function may vary in disease states such as CKD, depending on severity, comorbid conditions, and other factors. Therefore, circulating EPC count and function have been proposed as markers for vascular health, and their mobilization or replenishment may offer a potential therapy. Delivery of EPCs has shown success in repairing injured kidneys in animal models of both chronic and AKIs. This approach may be limited by EPC heterogeneity and incomplete characterization that may be addressed by standardization, engineering, or combination with other therapies. The aim of this article was to review the current state and recent advances in our understanding of the role of EPCs in homeostasis and conditions that may lead to their dysregulation in kidney diseases.