Abstract: A footrest for a child safety seat (20) includes a support (10) for supporting the lower side of an adherent child safety seat (20) and a footstep (13) that is attached to the support (10). The footstep (13) is adjustable in order to adapt to the length of the legs of the child (21) that is seated in the child safety seat (20). The footrest is equipped with an anchor (12) that is intended to be received in a space (24) between the upper side of an adherent seat (22) and the lower side of an adherent backrest (23) in a vehicle where the footrest is mounted.