An introduction to Additive Manufacturing (AM) technologies with a focus on 3D metal printing was given, and a short overview of the theory related to cellular porous structures, in particular, to Triply Periodic Minimal Surface (TPMS) structures was presented. Porous materials offer not only direct benefits such as lighter construction, material savings, and improved physical properties but also indirect advantages stemming from their widespread application in industries like aerospace and automotive, leading to fuel savings and environment protection. In this thesis the effect of specific weight and the type of cellular porous structure on the failure behaviour of a beam specimen subjected to bending was investigated. Three distinct structures (Schoen IWP, Fischer-Koch S, and Schoen F-RD), with five different specific weights, made from AlSi10Mg aluminium alloy using Direct Laser Metal Sintering (DMLS) technology were examined. A three-point bending test was conducted at room temperature using a Zwick/Roell 1456 universal testing machine to assess sample failure. The bending forces with respect to specimens’ deflection were recorded, and energy absorption and ductility indices were computed in order to investigate the effects of the three different porous structures and their specific weight on the bending strength of the considered specimens. It was observed from the experimental results that specimens with lower specific weight can bear relatively higher load compared to specimens with higher specific weight. Furthermore, in fractured specimens crack extension was influenced by the type of structure, suggesting that future control of crack propagation could be achieved through geometrical arrangements of pores.