Additive Manufacturing (AM) is an alternative manufacturing process, which has gained popularity and interest over the manufacturing industry for its benefits. Among the different AM processes, Selective Laser Melting (SLM) is one of the most promising ones since it enables the production of complex metallic parts from loose powder. Parts are produced adding material layer by layer with a high-powered laser that melts the powder bed. Thanks to this, optimal designs and light-weight components can be manufactured. Aluminum alloys have exceptional strength and stiffness in relation with its density, when compared with other materials. That is the main reason why it is a perfect candidate for this type of process, and nowadays it is extensively used for aerospace and automotive industry. Although these several advantages that SLM provides, parts manufactured with this process usually present porosity. Porosity is caused when non-appropriate parameters are used within the buildup process. Elevated levels of porosity lead to a decrease on the relative density value of the SLM pieces, being the cause of poor mechanical properties or even the fracture of it. The ability of producing complex parts is not enough, it must be complemented with high performance and high mechanical properties. Therefore, the relative density of SLM parts must be studied and enhanced to the highest possible value. In this project, relative density of AlSi10Mg samples produced with a SLM 280 will be studied. Relative density will be measured by changing the main process parameters used within the buildup process. The goal is to have a better understanding of the behavior of the relative density against those variations, and to find those parameters that achieve the highest value. With the best parameters obtained, tensile specimens will be produced and pulled to get values of the mechanical properties. This research should also serve as a guideline for future investigation of the same nature. The part performance is highly influenced by external uncontrollable factors such as the machine used, the powder and the environment of the chamber. That is the reason why it is so important to have a defined guideline with all the steps to be followed. Another reason to have a welldefined guideline is the fact that new materials are continuously being added to the SLM process. Therefore, even though the material properties are different, the process to achieve high relative density values should be similar.