Heart valve prosthesis, comprising a ring-shaped supporting structure (3) to be anchored at the valve annulus, and a valve leaflet (5) supported by the supporting structure. The supporting structure comprises a support wall portion (31), at which a root end (51) of the valve leaflet is connected, and a complementary wall portion (32) opposite the support wall portion, which supports a coaptation surface (33) adapted to be sealingly engaged by a free end (52) of the valve leaflet (5), and extending in a direction parallel to the direction of movement of the free end (52) of the valve leaflet (5) at the coaptation surface (33). The free end of the valve leaflet (5) is connected to the support wall portion or to the complementary wall portion by means of a traction member (55), dimensioned in such a way that the free end (52) of the valve leaflet (5) is stopped at the coaptation surface.
