Hemolytic anemia is a well-recognized complication of mechanical heart valve prosthesis but, as yet, has not been reported after mitral valve repair with chordal replacement. We report a case of severe hemolytic anemia after mitral valve repair with chordal replacement and Carpentier-Edwards annuloplasty ring insertion. Progressive prolapse of the anterior leaflet due to the artificial chordae being too long caused recurrent regurgitation which was responsible for the hemolysis. The patient also had idiopathic thrombocytopenic purpura, but successful second mitral valve repair was performed after high-dose gamma-globulin therapy.