Three-dimensional echocardiography offers great promise for improving the understanding of the mitral valve anatomy, function, and pathology. It may have important implications for medical or surgical management of different mitral valve disease. In this article we provide an overview of the three-dimensional anatomy of the mitral valve. Based on the studies using three-dimensional echocardiography we describe the topography of the mitral valve, its nonplanarity as well as dynamics of the mitral annulus. Furthermore, we review the use of three-dimensional echocardiography in the evaluation of different mitral valve disease. Three-dimensional echocardiography has become a new clinical standard in the assessment of the severity of mitral stenosis by means of accurate mitral valve area measurement. Also, unconventional indices, like the geometry and mitral valve volume may be assessed by three-dimensional echocardiography. It is a very suitable technique for monitoring the efficacy and complications of percutaneous mitral valvuloplasty. Three-dimensional echocardiography allows accurate identification and quantification of prolapse of individual segments of the mitral valve leaflets. Three-dimensional color flow imaging makes echocardiography an accurate method also in the assessment of mitral regurgitation severity. Finally, we outline three-dimensional echocardiography as a potentially useful guide for a surgeon, particularly in mitral valve repair.