BACKGROUND The optimal treatment strategy following a failed mitral valve repair remains unclear. This study evaluated early and long-term outcomes of redo mitral valve repair (MVr) and replacement (MVR) after prior mitral valve repair. METHODS Patients undergoing redo mitral valve surgery after prior mitral valve repair at a single institution between 2002 and 2014 were reviewed. Primary outcomes included operative mortality (30-day or in-hospital mortality) and long-term freedom from mitral valve reoperation and death. Secondary outcomes included postoperative complications. RESULTS 305 patients underwent redo MVr (n = 48) or MVR (n = 257) after prior mitral valve repair. Concomitant procedures included tricuspid valve repair or replacement (23%), aortic valve replacement (6%), and coronary artery bypass grafting (4%), with no differences between cohorts. 18% were performed via right mini-thoracotomy (24% MVr vs 18% MVR, P = 0.31). Unadjusted and risk-adjusted operative mortality were lower with MVr (0% vs 8%, P = 0.04). Rates of postoperative complications were similar except for blood product transfusion (35% MVr vs 59% MVR, P = 0.003) and prolonged mechanical ventilation (8% MVr vs 29% MVR, P = 0.003). Long-term freedom from mortality was comparable: 96% MVr versus 86% MVR at 1 year and 78% MVr versus 68% MVR at 5 years (P = 0.29). CONCLUSIONS When technically feasible, mitral valve re-repair can be safely performed with outcomes comparable to MVR.