A heart valve (600) includes a valve body (330) made of a flexible material such as pericardium. The valve body is made of two layers of material, an outer layer, and an inner layer that defines a plurality of leaflets (354). The leaflets of the inner layer are attached to the outer layer. In some embodiments the valve body is made by cutting a single piece of flat source tissue, folding the cut tissue and forming it into a tubular pattern having the inner and outer layers. The multi-layer valve body can be mounted on a stent (500) for delivery within a patient's heart.
