MicroRNAs (miRNAs) are a group of endogenous small non-coding RNAs, which play important gene regulatory roles at the post-transcriptional level by binding to the 3′ untranslated region of the targeted mRNAs. MiRNAs possess tissue-specific signatures and have been found involved in various pathophysiological processes. Recent reports have demonstrated that miRNAs are stably present in blood circulation in the form of microvesicles, exosome, microparticle, and apoptotic bodies; and the plasma levels of specific miRNAs have been proven as potential biomarkers for diagnosis and prognosis of cancers. Many articles have also reported that miRNAs can serve as important diagnostic biomarkers for cardiovascular diseases. Here we reviewed the roles of circulating miRNAs as potential biomarkers for cardiovascular diseases, including acute myocardial infarction, heart failure, coronary artery disease, and diabetes mellitus.