Abstract The preparation of materials with enhanced magnetocaloric properties is crucial for magnetic refrigeration. In this study, Nd-doped Gd5Si4 microparticles and nanomaterials were synthesized using the reduction-diffusion method. The impact of Nd doping with varying compositions on the structure and entropy change properties of the materials was investigated. The Curie temperatures of both the micron and nanosized materials ranged from 190 to 210 K, which were lower than previously reported values. The micron-sized samples doped with 1% Nd exhibited superior magnetocaloric properties, demonstrating a maximum entropy change of 4.98 J·kg-1·K-1 at 5 T over a wide temperature range of approximately 70 K, with an entropy change exceeding 4 J·kg-1 ·K-1. Conversely, the nanomaterials had broader entropy change peaks but lower values. All the samples exhibited a second-order phase transition, as confirmed by Arrott plots.