Over the past two decades interest in mitral valve regurgitation has increased as a result of the development of new technologies that have expanded the number of patients who can potentially benefit from mitral regurgitation treatments. To develop new devices for the treatment of mitral regurgitation, the focus has been placed on the functional anatomy and pathophysiology of the mitral valve, with the use of the most advanced methods of cardiac imaging that allow the best visualization of the mitral valve and a perfect understanding of the complexity of a specific disease. Mitral regurgitation is still underdiagnosed and undertreated in a substantial number of patients who have poor survival. Therefore, the priority should be to identify and treat these patients to increase their survival and quality of life. To achieve this goal, general physicians and cardiologists must be aware of all the treatment options that are currently available in dedicated centres of excellence. Patients referred to these centres can benefit from a tailored heart team-based approach. The aim of this Review is to analyse the basic principles of mitral regurgitation, discussing new concepts on the pathophysiology of the mitral valve that have been developed to facilitate the selection of patients for transcatheter procedures. We also describe the indications and timing of treatment, contemporary surgical and transcatheter techniques and the heart team approach, and highlight the need for centres of excellence.