A 76-year-old woman was admitted to our hospital complaining of dyspnea on effort. Echocardiography showed severe mitral regurgitation. Her medical history indicated that she was allergic to metal, and skin patch tests were positive for nickel, cobalt, platinum, manganese, iridium, chromium, and zinc. Valvuloplasty involved triangular resection of P2 and mitral valve annuloplasty with a metal-free, 29 mm Tailor Flexible Ring. The sternum was closed using polyester non-absorbable sutures instead of surgical steel wire. Her postoperative course was uneventful and she was discharged on postoperative day 21. Nine months later, she is well and free of allergic symptoms.