The patient was a 68-year-old woman who had undergone initial mitral repair at 24 years of age, and had undergone mitral replacement using the Björk-Shiley convexo-concave valve at 30 years of age. She developed exertional dyspnea 38 years after mitral replacement with hemolytic anemia. Precise examination revealed mitral stenosis and perivalvular leak. At the reoperation, severe calcified pannus was found at the ventricular side just beneath the mitral artificial valve, and made stenosis with the inadequate leaflet opening. The mitral valve remnant ring was severely calcified and the sawing ring was detached partially. Repeated valve replacement was successfully done by the reinforcement of the mitral valve ring with xenopericardium.