A "tissue valve type" heart valve prosthesis is disclosed which has a biocompatible plastic sewing ring adapted to be surgically implanted into the mitral, aortic or tricuspid annulus of the human heart. The sewing ring has internal square threads and a biocompatible fabric mesh or cloth is embedded into the sewing ring so that the cloth can be fully wrapped around the sewing ring covering all of its plastic surfaces except for the internally protruding threads. A biocompatible plastic stent support ring has externally disposed threads to lock with the threads of the sewing ring in approximately one turn, or less. The stent support ring also embeds a biocompatible fabric mesh which can be wrapped around the stent support ring to cover all of its plastic surfaces, except for the protruding threads, and to form a cloth pocket wherein a solid stent is mounted. A porcine trileaflet valve is mounted to the stent. When the heart valve prosthesis is as implanted into the heart, the threads of the sewing ring and of the stent support ring interlock, and there are no plastic or metal surfaces, uncovered by biocompatible fabric, to be exposed to blood flow. Processes for making the solid metal stent by laser cutting, and the sewing and stent support rings by a specifically adapted plastic molding procedure, are also disclosed.