Abstract: A pick-up truck box extender flip gate is provided. The truck box extender flip gate of the current application is comprised of; 1) a tail gate attaching frame, 2) two side faces, each of which is comprised of one guide and one metal frame. 3) a first front face that is rotatably connected to the two guides, and 4) a second front face that is rotatably connected to the first front face via hinges. When the pick-up truck box extender flip gate is in retracted position, the two guides are embedded in two rectangular metal frames which are welded to both ends of the tail gate frame. The first front face and the second front face are overlapped with the tailgate-attaching frame when the flip gate is retracted. In extended position, the first front face and second front faces come out of the attaching frame to extend the pick-up truck cargo box space. The first and second front faces have racks for holding bicycle wheel or long ladder's leg.