Development of an intracardiac fistula is a rare complication after mitral valve replacement. In the literature we have found six cases of left ventricular-coronary sinus fistula and another one of left ventricular-coronary sinus and right atrial fistula. We report the history and course of a patient in whom a left ventricular-coronary sinus and right ventricular fistula developed late after mitral valve replacement. The current study examines this type of intracardiac shunt, and presents our report on a left ventricular-coronary sinus and right ventricular fistula complication.