The lightweight multi-material design is often used to achieve improved mechanical performance, better thermal properties, weight savings and cost reduction. The lightweight structures can usually be fabricated as a combination of different materials such as advanced steels, light metals (i.e. aluminium, magnesium and their alloys) and cellular materials (e.g. polymeric and metallic foams). The major challenge, and one of the main cost drivers of multi-material design, is the joining of parts made of different materials. The most common and cost-effective joining solution is the mechanical and/or adhesive bonding. The light foam-filled structures made of metal alloys have been developed to avoid the additional joining step by taking full advantage of the powder compact foaming (PCF) technique used to fabricate metallic foams. The aim of this study was to analyse the mechanical performance of the ex-situ (the aluminium alloy tube is filled with an aluminium alloy foam after its formation) and in-situ (the aluminium alloy tube is filled with an aluminium alloy foam during its formation) foam-filled tubes. Different shapes and thicknesses of the outer tubes have been consider, as well different foam filler types. The specimens have been subjected to various loading conditions (e.g. compression, bending) and loading velocities (e.g. quasi-static, dynamic). Results confirm that the in-situ foam filled tubes offer a more stable crush performance. The results also demonstrate that heat treated aluminium alloy structures ensure high ductility and very good crashworthiness since they deform without formation of early cracks, which is a pre-requisite for good and reliable crashworthiness behaviour.