MicroRNAs (miRNAs) are composed of a group of endogenous and noncoding small RNAs which control expression of complementary target mRNAs. The extended functions of miRNAs enhance the complexity of gene-regulatory processes in cardiovascular and cerebrovascular diseases. Indeed, recent studies have shown that miRNAs are closely related to myocardial infarction, heart failure, atrial fibrillation, cardiomyopathy, hypertension, angiogenesis, coronary artery disease, dyslipidaemia, stroke, and so forth. These findings suggest a new therapeutic pointcut for cardiovascular and cerebrovascular diseases and show the extensive therapeutic potential of miRNA regulation. Moreover, it has been shown that circulating extracellular miRNAs are stable in bodily fluids, which indicates circulating miRNAs as potential and emerging biomarkers for noninvasive diagnosis. This review highlights the most recent findings indicative of circulating miRNAs as potential clinical biomarkers for diagnosis of cardiovascular and cerebrovascular diseases.