Abstract: A crib liner for lining a baby crib including a flexible base member for being located beneath a mattress of the crib, and a side guard attached to the periphery of the base member for lining the side walls of the crib so as to keep a baby's arms and legs inside the crib while the baby is lying down therein. The side guard is preferably attached to the base member continuously along the periphery thereof. A plurality of fasteners are attached to the side guard for attaching the crib liner to the posts and bars of the crib. In a preferred embodiment of the present invention, the base member is formed from a fabric material, and the side guard is sewn onto, or otherwise attached to the base member, preferably continuously therearound.