The invention relates to a prosthetic valve which is endoluminally placeable and comprises a tubular support radially deformable with respect to a main axis (X-X) from an unfolded implanting position to a folded setting position. A flexible plug connected to the tubular support and deformable between a blocking position in which it is transversally stretched and a releasing position in which it is transversally contracted by the action of a flow circulating through said tubular support. The inventive valve also comprises a rigid chord which extends generally along the generatrix of the tubular support and is connected thereto at least at two points which are remote from each other along the axis thereof.