The number of patients undergoing surgery for mitral regurgitation has been increasing. While the incidence of rheumatic mitral regurgitation has considerably decreased, ischemic or functional mitral regurgitation is a growing public health problem. This is at least partially because of an increase in life-style related diseases and advances in the management of patients with heart failure. Mitral valve repair is chosen when the valve is suitable for repair and appropriate surgical skill and expertise are available. Transthoracic or transesophageal echocardiography is important for the assessment of reparability by defining cause, mechanism, and location of lesions. Observational evidence suggests that the major surgical determinant of improved long-term outcome is valve repair. Chronic atrial fibrillation and mechanical valve replacement are associated with high risk of embolism and hemorrhagic complications (due to intensive anticoagulation). Increased mortality after replacement emphasizes the importance of early detection and assessment of mitral valve diseases. Experimental studies have shown successful and reliable mitral clip through trans-septal catheterization. A randomised trial comparing percutaneous mitral clip and surgery is in progress in the USA. While there might be important limitations, it is expected to be valuable in patients with impaired cardiac function due to ischemic or functional mitral regurgitation. Valvular function, incidence of leak (paravalvular and transvalvular), grade of regurgitation, and cardiac function are evaluated routinely at postoperative follow-up. The possibility of endocarditis and constrictive pericarditis should be considered. Transthoracic echocardiography is often limited when assessing a prosthetic valve because of the effect of acoustic shadowing. Transesophageal echocardiography provides excellent visualization especially in patients with mechanical valve replacement. The degree of obstruction varies with the type and size of the valve. Indices of echocardiography should be compared to the baseline or previous data.