A number of centers have recorded a significant incidence of primary tissue valve failure with the Ionescu-Shiley pericardial valve. Clinically, Endothelialization and host tissue ingrowth on the cloth and the leaflets at the edge of the frame greatly reduced the amounts of abrasion and the incidence of tissue failure. In most cases severe regurgitation was caused by leaflet tears adjacent to the edge of the cloth-covered stent. We report a case of spontaneous disruption of one cusp on the Ionescu-Shiley pericardial xenograft in mitral position at 6years and its successful management.