The present invention is a truck bed liner having two side walls, a front wall, a bottom, and a rear wall, the bottom further having an integrated liner incorporated into it. The divider is formed by either molding or cutting slots on three sides of the liner bottom. The fourth side is molded or cut into a living hinge. The living hinge allows the unattached portion of the truck bed liner bottom to move freely about the hinge. The side walls of the truck bed liner include receiving channels into which the hinged dividers are locked into place. A latch is molded into and extends from the lower aspect of each sidewall at a point in which when the divider is placed into its horizontal position, will hold it in place. In operation, an operator can position the hinged divider to a 90.degree. position with respect to the bottom and lock it into the receiving channels found on the side walls. Once locked into position, a compartment is created on each side of the raised wall. When compartmentalization is no longer needed, the hinged portion of the liner can be removed from the side wall channels and placed into a horizontal position, being locked into position by the latches.