A transcatheter atrio-ventricular valve prosthesis 1 for functionally replacement of an atrio-ventricular valve (9) in a connection channel 18, having a circumferential connection channel wall structure (18'), between atrial and ventricular chambers of a heart, comprising an inner device (19) to be disposed in the interior of the connection channel (18), the inner device having a circumferential support structure (21) which is radially expandable and having a valve (22) attached to the circumferential support structure, and an outer device (25) to be disposed on the exterior of the connection channel, wherein the outer device at least partly extends around the inner device in a radial distance to the inner device, wherein the inner and outer devices form a clamping mechanism for clamping the circumferential connection channel wall structure there between, wherein the outer device is configured to form a ring (26), the circumferential support structure comprises an outer circumferential groove (35), and the ring is configured to be aligned to the outer circumferential groove.
