We analyzed the risk of mitral valve re-replacement (re-MVR) in patients over 70-year-old. Surgical and late follow-up results were compared between 14 elderly patients over 70-year-old (group I) and 23 patients aged from 60 to 69-year-old (group II) who underwent re-MVR due to primary tissue failure (PTF). Donation of autologous blood and a rate of replaced valve prosthesis (mechanical/biological) were different between the two groups. There were no differences in the other factors such as clinical profile, preoperative organ function, operative characteristics, post operative relating factors. No operative death occurred in both groups. There was one hospital death in group I (a hospital mortality rate of 7.1%). The cause of death was related to massive cerebral infarction due to anticoagulant-related thromboembolic event. 4-64 months after re-MVR, the improvement of a NYHA function class was I-II in the two groups. With improvement in myocardial protection and intraoperative strategies, the operative risk in patients undergoing re-MVR over 70-year-old has been markedly reduced. Surgical results in aged patients were satisfactory and age alone is not a contraindication for this operation. The re-MVR in aged patients should be done at the early stage of PTF before progress of cardiac failure.