Neochordae construction using an expanded polytetrafluoroethylene suture is an accepted surgical technique to correct mitral regurgitation due to mitral valve prolapse. We report two cases of intermediate and early rupture of CV-5 expanded polytetrafluoroethylene neochordae after mitral valve repair. As a result of these cases, we now use CV-3 expanded polytetrafluoroethylene for neochordae construction with no failures. (Ann Thorac Surg 2011;92:341-3) (C) 2011 by The Society of Thoracic Surgeons