 This paper reviews the microstructures and mechanical properties of three different metallic alloys produced through additive manufacturing, AM, processes. It focuses on the effect of AM processing on the formation of metallurgical defects and microstructures, as well as how these affect mechanical properties. For titanium alloy T6L4V, the paper discusses the influence of AM on the development of metallurgical defects, such as porosity and cracks, which can lead to reduced strength and ductility. In addition, it examines the effect of surface roughness and build atmosphere on mechanical properties. Steel alloys are also discussed with the paper focusing on the impact of rapid solidification inherent to AM on phase selection and resulting mechanical properties. Finally, the paper compares the mechanical properties of AM produced alloys to those produced via conventional methods.