A method of treating a defective mitral valve includes percutaneously advancing a prosthetic device into a patient's heart. The prosthetic device includes an insert member and anchoring member. The prosthetic device is contained within a sheath along a distal end of a delivery catheter during advancement. The anchoring member is secured to a muscular wall of the left ventricle and the insert member self-expands between native leaflets of the mitral valve. The insert member preferably includes a biocompatible fabric outer layer, a passageway, and a valve member disposed within the passageway. After deployment, the native leaflets of the mitral valve form a tight seal against the fabric outer layer of the insert member for preventing regurgitation, while blood passes through the passageway of the insert member for allowing blood to pass from the left atrium to the left ventricle.