Although porcine mitral bioprostheses provide predictably good long-term outcomes, unexpected leaflet tears leading to abrupt haemodynamic changes may occur. We report on a patient who presented with acute dyspnea due to cuspal tear of a porcine bioprosthetic mitral valve causing severe mitral regurgitation, her condition was subsequently complicated by systemic infection, probably pneumonia, and was successfully managed with urgent redo-mitral valve replacement.