Abstract: An air cargo container includes a base, side walls and a roof, the side walls and roof being made of panels of a composite structural sheet material which is capable of sustaining the tensile, compressive and shear loads to be carried by the container, the panels being connected together and to the base along their edges in the absence of a structural framework. The composite structural material includes three layers, a core layer of a closed cell foam and outer structural layers including thermo-setting plastics sheet material and aluminium alloy sheet material. At least some of the side walls are vertical and planar over their entire extents and, at their lower edges, are surrounded by a laterally projecting flange for use in anchoring the container in the cargo hold.