Atherosclerosis is due to inflammation and endothelial dysfunction and damage caused by a variety of factors. Dysfunction of endothelial progenitor cells (EPCs) that differentiate into mature endothelial cell contributes to the development of atherosclerosis. Both the number and functionality of EPCs are regulated, particularly in vascular repair. Further elucidation of the role of EPCs in atherosclerosis could potentially enable the development of novel strategies for prevention and treatment of pathological changes in atherosclerosis.