Abstract: This relates to a clamp assembly for engagement with a lowermost rear pallet board in a truck or trailer so as to restrain the pallet and all preceding pallets and those stacked thereon against rearward movement. The pallet clamp assembly includes a suitable track recessed in the trailer bed or floor and a pallet clamp which is adjustable longitudinally of the track and which in its inoperative position is fully seated and retained in the track against movement. The pallet clamp is of a simple construction and once released against movement longitudinally of the track may be easily manually positioned relative to a pallet and then locked relative to the track in its adjusted position. In a like manner, when it is desired to unload the truck or trailer, the pallet clamp may be readily released with respect to the track, moved rearwardly away from the pallet and fully seated within the track so as to in no way interfere with the unloading of pallets from the truck or trailer.