Commercial powders of magnesium were processed by high-energy ball milling (HEBM) using a two-stage composite process. The microstructural and morphological evolution of the powders was studied using scanning electron microscopy (SEM), energy-dispersive spectrometry (EDX), and X-ray diffraction (XRD). From the results obtained, it was determined that the energy transferred by means of the control of balls size and high milling speeds allowed the particles of Mg powder to deform and fracture, achieving grain refinement and particle size reduction in a relatively short time. Likewise, milling energy calculations were made to determine the effect of the milling parameters. Subsequently, milled powders were compacted and HIPed reaching a densification of 95%. Finally, mechanical tests showed that the developed process increased the hardness and compressive strength of Mg compared to the material obtained by casting. © 2022, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.