Endothelial dysfunction induced by various atherosclerotic risk factors can initiate the process of atherosclerosis. Endothelial progenitor cells (EPCs), which have been considered as the precursor of endothelial cells (ECs), play an important role in the maintenance of endothelial function. The inverse association between high-density lipoprotein (HDL) levels and the risk of coronary heart disease (CHD) events has been demonstrated. Furthermore, accumulating studies suggest an important role of HDL in preventing and restoring endothelial dysfunction. Also, the importance of apolipoprotein A-I (apoA-I) in protection against cardiovascular disease is widely researched. Recently, it is shown that HDL could protect cultured human EPCs in different ways. Here, we review the studies on the association between HDL, its functional components, including apoA-I and mimetic peptide, and endothelial function and the underlying mechanisms that have been carried out so far.