A bracket (10) for mounting accessories on a pick-up truck cab (20) consisting of a Z-shaped elongated body (22) having a forward upper horizontal mounting flange (24), a rearward lower horizontal mounting flange (28), and an integral arcuate upright section (26) located in between. The upright section (26) conforms to the shape of the truck cab (20) and includes a recessed cavity (30) in reverse image of a truck third brake light socket (32) that is formed within the truck cab. A number of threaded fasteners (54) are used for attaching the third brake light onto existing threaded mounting holes (38) in the truck third brake light socket (32) when the bracket is inserted into the socket (32), thereby securely retaining both the light and the bracket in place.