Mitral valve regurgitation is the second most common valvular heart disease in Europe, and an estimated 10% of individuals older than 75 years have severe mitral regurgitation. Mitral valve repair is the preferred strategy to treat mitral regurgitation and is associated with better outcomes than mitral valve replacement. Despite the proven efficacy of surgical repair, available data in functional aetiologies reported a not negligible rate of echocardiographically detected severe mitral regurgitation within ten years of the index procedure, in some cases resulting in redo interventions. Data on the optimal management of patients with failed mitral repair remain limited. The aim of this review is to present the available approaches for treating failed mitral valve repair and to describe criteria for selecting the most appropriate strategy on the basis of the underlying mechanism of repair failure, with respect to possible surgical re-repair and novel transcatheter edge-to-edge repair techniques in presence of favourable mitral valve anatomies.