A 70-year-old patient (NYHA IV), who required a Carpentier pericardial prosthetic valve for mitral valve replacement, developed a type 2 intraoperative left ventricular rupture (mid portion of left ventricle) with cataclysmic bleeding. A successful repair with intraventricular dacron patch was performed by suturing the patch on the prosthetic sewing ring and through the ventricular wall using pledgetted stitches. The postoperative course was satisfactory without extensive myocardial necrosis and the patient is well 7 months later without angina and with reduced dyspnoea (NYHA II). Pre and postoperative left ventricular function were similar. These ventricular injuries after mitral surgery are well known but always difficult to manage and characterized by a high mortality rate. This technique (including prosthetic valve removal and intraventricular repair) seems to provide a greater chance of success than other external repair techniques. The best treatment remains prevention and consists in preserving the posterior mitral leaflet, avoiding extensive decalcification or resection and using low profiled prosthetic mitral valves. Likewise, mitral repair must be attempted as often as possible, because, in our opinion, this complication has never been reported in conservative mitral surgery.