The disclosure relates to a collapsible shipping container adapted for use in shipping various cargo on trucks or by rail or by means of aircraft or any other suitable transport means such as sea going vessels or the like. The container being provided with six side structures removably connected together so as to permit compact shipping of the containers in disassembled condition to reduce the bulk thereof so that they may be transported from one area to another returned to the point of origin for reuse. The containers being provided with disengageable fixture means for holding the respective panels together which fixture means is readily operable to disassemble the panel structures of the container so as to open the same for the placement of cargo therein or for the removal of cargo therefrom. The container being provided with fixture means on the inside thereof accessible from the inside only and with a locked door in one of the panels to provide authorized access to the removable fixtures on the inside of the container so as to permit disassembly thereof or opening the container to remove cargo therefrom. The structure of the container comprises tubular frame members having a pair of flanges disposed at substantially right angles to each other and socket portions in the ends of the tube members with prong structures connected to the corners of at least two of the panel structures such that the prongs may fit into open ends of the frame members of some of the panel structures to interlock the entire assembly when the removable fixture means is projected through the flanges of the frame members and fastened relative thereto.