Endothelial dysfunction reflected by reduced nitric oxide availability is nowadays considered as a causative factor of atherosclerosis. A variety of biomarkers has been used as indicators of endothelial dysfunction in cardiovascular disease. Discovered just over a decade ago, microRNAs have evoked a great deal of interest, due to their importance for many aspects of homeostasis and disease. miRNAs comprise a novel class of endogenous, single-stranded, short RNA sequences able to regulate gene expression by binding to complementary sequences on mRNAs According to a growing body of evidence, they have been implicated in the regulation of several human physiological processes. They have been shown to participate in cardiovascular disease pathogenesis including atherosclerosis and endothelial dysfunction and this may have important clinical implications.