The invention relates to a mitral heart valve prosthesis and a delivery catheter to carry and deploy such a prosthesis. The invention allows to effectively treat a pathology related to moderate to severe mitral regurgitation. Such a prosthesis implantable by catheterism includes mainly a docking station and a leaflet cooperating with the docking station. The leaflet is advantageously arranged in a configuration close to a posterior leaflet of a native mitral valve of a patient.