Abstract: A rail attachment apparatus is set forth for use in combination with pockets formed within the side walls of a truck bed. The pockets are formed with side walls of a predetermined height. The apparatus includes an upper post integrally secured to a positioning plate overlying an opening defining the pocket with a threaded rod extending therethrough. The threaded rod extends downwardly through a depth post into threaded engagement with a latch plate integrally secured to the depth post. The latch plate is formed of a generally rectangular planar configuration with rounded corners for positioning within the pocket and rotated ninety degrees after initial positioning to engage underlying edges of the pocket walls whereupon tightening by use of an overlying threaded fastener, the assembly grasps the pocket walls and enables the depth post to be telescopingly received within the upper post to secure the latch plate in position.