Calcification of the mitral annulus is always a technical complication in mitral surgery and standard procedures are often difficult to perform; mitral valve replacement can be dangerous with a high risk of perioperative heart rupture, and reconstructive surgery is often contraindicated. Nevertheless in this case of posterior leaflet prolapse with annular calcification valve repair was performed, after complete calcium debridement causing annulus disruption and atrio-ventricular discontinuity, by means of a straddling atrio-ventricular pericardial patch and the sliding leaflet technique.