Mitral regurgitation (MR) is a common cause of heart failure but may also remain silent without either symptoms or altered cardiac function. In the latter case, management is still controversial and biomarkers could be an important means to solving remaining issues in MR management. As objective markers of myocardial stress and early left ventricular dysfunction, biomarkers may for example facilitate the identification of patients with benefit from early surgery of degenerative MR. The most studied biomarkers are the natriuretic peptides (NPs), especially brain NP, as well as its N terminal prohormone. In addition, other biologically relevant biomarkers have been recently proposed based on proteomic approaches. Finally, the large family of microRNA, that are the most abundant non-coding RNA, may also be of future interest. In this review, we will summarize the current knowledge about NPs in degenerative and functional MR, and general "omic" discoveries and microRNAs.