Some composites of barium ferrites activated with the neodymium ions (Nd3+) of composition (20)BaO:(80-x)γFe2O3:(x)Nd2O3 (x = 0, 1 and 2 mol%) were synthesized using the modified mechanical alloying for the first time. The influence of varying Nd3+ concentrations on the morphologies, microstructures, and magnetic characteristics of these composites were evaluated. In addition, the microwave (MW) reflection loss, complex relative permittivity, and permeability of the studied composites in the frequency range of 8.2–12.4 GHz were analysed using the Nicholson-Ross-Weir (NRW) method. The inclusion of Nd3+ in the proposed composites was discerned to influence the permittivity, permeability and reflection loss significantly in the MW X-band region.