We report a case of left ventricular rupture and left ventricular-right atrial communication after mitral valve re-replacement. A 53-year-old man was admitted to our hospital for a primary tissue failure of mitral xenograft. On June 4, 1997, he underwent mitral valve re-replacement. At 12 post operative day, he was suffered from unexpected dyspnea. The transesophageal echocardiography showed floated mitral valve and left ventricular-right atrial communication. The emergent operation was done. At the operation, posterior mitral annulus was disrupted and the disruption reached to a membranous septum. A communication was directly closed, mitral annulus was repaired with perigard and one size smaller mitral valve was implanted. The patient was discharged and returned to social life.