Surgery for degenerative mitral regurgitation has become complex. Preservation of annulo-ventricular continuity through the chordae tendineae is an important determinant of operative survival, postoperative left ventricular function, long-term survival, and quality of life. Some cardiologists believe that NYHA I function is never achieved after conventional mitral replacement with chordal transection. Valve repair is the procedure of choice but when valve replacement is inevitable every effort should be made to preserve the posterior leaflet and its chordal attachments. Valve replacement with preservation of the subvalvar apparatus provides a functional outcome similar to that after valve repair but usually leads to life long anti-coagulation.