Abstract: A device for retaining sheets about the edge of a mattress is adapted to be placed between the mattress and a support surface with a portion of the sheet received in a channel-like recess of the retainer and held therein to restrict undesired withdrawal of the sheet therefrom. The retainer has a flat shank portion and a downwardly directed lip at one end thereof with the lip defining a recess for receiving a portion of the sheet therebehind. In a modified structure the sheet retainer includes a first and second member which are movable from a sheet retaining position to a non-sheet retaining position to facilitate insertion of a sheet therewithin. The members define a channel recess which receives a portion of the other member, with the members cooperating to restrict inadvertent withdrawal of the sheet from the retainer when received in the device.