A cargo box (10) reinforcement system (20) includes an upper front panel reinforcement (22) securable to a cargo box front panel (18) and side wall panels (14, 16). The system (20) including a pair of side reinforcements (24, 26). Each side reinforcement (24, 26) is securable to one side of the pair of side panels (14, 16) of the cargo box (10). Each side reinforcement (24, 26) is secured with an end (40) of the upper front panel reinforcement (22). Also, the system (20) includes a pair of gussets (28, 30). Each gusset (28, 30) is coupled with the upper front panel reinforcement (22) and one of the pair of side reinforcements (24, 26).