This work aims at investigating the impact behavior of an additively manufactured AlSi10Mg alloy subjected to different heat-treatment conditions. The commonly used heat-treatment routes were compared with a novel route (HPT6), which combines hot isostatic pressing (HIP), gas quenching, and ageing at high pressures. The as-built and treated alloy was characterized by Charpy impact testing and several microstructural and fractographic techniques, such as scanning electron microscopy, transmission electron microscopy (TEM), and X-ray diffraction. The as-built material displayed a very fine non-equilibrium microstructure, which led to a high impact strength but limited absorbed energy. Low-temperature annealing severely modified the starting microstructure of the alloy and restored its equilibrium condition. Even though this alloy did not suffer from strength loss, its absorbed energy increased significantly …