Abstract: A heart valve prosthesis includes a collapsible stent and a one-piece multi-leaflet valve. The stent includes at least one length of wire having a series of turns forming a spring-like stent. The one-piece multi-leaflet valve is attached to the stent and includes a cylinder of polyester material secured thereto at three points. The stent is collapsible in a radial direction between a contracted state and an expanded state. The contracted state has a radial dimension smaller than a radial dimension of the expanded state. The stent is spring biased toward the expanded state such that it occupies an active state when implanted into a heart. The active state has a radial dimension that is between the radial dimension of the contracted state and the radial dimension of the expanded state such that a radial load generated by the bias of the collapsible stent is sufficient to retain the heart valve prosthesis in the heart.