A new partial translocation technique to repair left ventricular rupture after mitral valve replacement and reimplant a mitral prosthesis is described. We repaired a tear from the interior by using mattress stitches buttressed with strips of Dacron felt, constructed a new annulus with a crescent-shaped piece of bovine pericardium on the left atrial wall above the repaired mitral annulus, and implanted a new prosthesis by using the newly constructed mitral annulus. We consider avoidance of mechanical stress by the prosthesis on the repaired site crucial to a successful outcome, and this new method is useful.