Abstract: A cover assembly is shown for a pickup truck having an open-topped bed. Supported from the top of the side panels of the truck bed is a track that is positioned within the bed and is formed by a pair of parallel rails of C-channel configuration, having an elongated slot extending longitudinally thereof and facing a similar slot on the other rail. The front end of each rail extends partially into a storage box that is fitted down into the truck bed at the front thereof, and this box extends transversely thereof. The track is furnished with a travelling rectangular frame having a pair of flexible side portions formed by a plurality of hinged slide bars that travel within the parallel rails. These slide bars are separated by a short link so that this travelling frame may fold into accordion folds when the frame is shifted forwardly into the storage box. A sheet of flexible material is fitted over the travelling rectangular frame for covering the truck bed.