MicroRNAs (miRNAs) are small noncoding RNA molecules that regulate gene and protein expression by translational repression and/or mRNA degradation. miRNAs are implicated in the pathogenesis of various cardiovascular diseases and have become potential targets for therapeutic intervention. Their stability and presence in variety of readily accessible cell types including whole blood, serum, plasma, and other body fluids render them as potential source of a clinical biomarker. This review provides a brief overview of miRNA biogenesis and function, the diagnostic potential of circulating extracellular miRNA and their specific role in vivo in various cardiovascular settings, and their future perspective as clinical biomarkers. It is clearly evident from experimental studies that miRNAs are responsible for the regulation of several biological functions and alterations in cardiovascular diseases. Current data supports the concept of using circulating miRNAs as a biomarker in cardiovascular disease. It remains to be seen, however, whether circulating miRNAs can fulfil this role to improve risk and severity prediction.