We report two non-surgical cases of pseudoaneurysm of the left ventricle after mitral valve replacement. Two patients underwent uncomplicated mitral valve replacement with Ionescu-Shiley and Carpentier-Edwards bioprosthesis respectively, and both had good early postoperative course with no symptoms. Left ventriculogram one month after operation showed subvalvular pseudoaneurysm of the left ventricle in both patients. Two patients were in New York Heart Association Functional Class I with digitalis and diuretics and have left ventriculogram had done five years postoperatively. Pseudoaneurysm of the left ventricle without a surgical repair disappeared in one patient, and revealed no enlargement in the other. There still remain controversies regarding the treatment of pseudoaneurysm of the left ventricle following mitral valve replacement.