Abstract: A novel, long lasting prosthetic heart valve compatible with implantation in a human natural heart valve annulus. The prosthetic heart valve comprises a trileaflet heart valve apparatus which in form, dimension, and function resembles a human trileaflet heart valve, but which is formed of synthetic resinous material. A seamless supporting frame capable of annular deformation and limited perimetric expansion during each heartbeat is totally enveloped in an essentially biologically inert cylindrical cover to form a cusp supporting stent for the valve leaflet apparatus. The free top and bottom edges of the cylindrical cover are disposed on the exterior of the stent and everted outward to provide at least one sewing ring. Valve embodiments comprise aortic and mitral implantable valves.