Covering device (1) and mechanism for door shackles comprising a support body (2) to be fastened to a door and having a hole (3), a first covering element (4) having an opening (5) and to be associated to the support body (2) so as to cover a first portion of the support body (2), and a second covering element (7) having a hole (8) corresponding to the hole (3) of the support body (2), which second element can be placed beside the first covering element (4) in the opening (5) and can be associated to the support body (2) so as to cover a second portion of the support body (2). The second covering element (7) is concentric with respect to the first covering element (4) and is basically disc-shaped.