Abstract: A flexible cap for a truck bed comprises a plurality of supports intermediately positioned along the truck bed, with a flexible material being stretched over the supports to form the cap. Braces between the supports may be folded into a collapsed position so as to permit the supports to be slid along guide tracks positioned along opposite sides of the truck bed. The supports may be slid into an abutting relationship so as to result in the cap being totally collapsed into a compact package in a forward part of the truck bed. If desired, the cap may be only partially collapsed so as to leave a portion of the truck bed exposed while a further portion of the bed is still sheltered.