Abstract: A mobile storage container readily disposable under the frame of a bed supported off the ground by legs. The container includes a body structure having a bottom wall, side walls, and an open top, a cover of flexible material for the open top and for fitting and extending over the side walls, and caster assemblies for supporting the body for rolling movement. Hand-hold cutouts provided in the side walls of the body, and corresponding openings in the cover, provide ventilation of the container interior, and for ready grasping thereof for movement under and from beneath a bed. The height of the container from the bottom of the caster assemblies to the top of the side walls is less than the height of the bed frame supported off the ground by legs. The caster assemblies are recessed to provide maximum storage volume and maximum mobility for a minimum container height, and the cover is transparent so that the container contents may be viewed without removal thereof.