Sixty-eight patients with severe rheumatic mitral insufficiency MI with or without stenosis were randomized into mitral valve replacement with preservation of the subvalvular apparatus (MVRP, n = 35) and conventional mitral valve replacement (MVR, n = 33) groups. Total subvalvular apparatus was preserved in MVRP patients; the preserved tissue was placed near the posterior wall of the left ventricle, then plicated and reaffixed to one-fourth of the annular circumference in the posterior annulus. Mechanical ventilation and ICU times were shorter in the MVRP group; there were also fewer ventricular arrhythmias and less need for inotropic support in this group. One year follow up echocardiography data showed better preserved left ventricular ejection fraction (LVEF) and better recovery of heart size after MRVP. There was no sign of preserved valvular tissue interfering with prosthetic valve function or causing left ventricular outflow tract (LVOT) obstruction. This modified MVRP technique is simple, effective and without risk of LVOT obstruction. In severe rheumatic MI patients the outcome of MVRP is superior to that of conventional MVR.