Electrical discharge machining (EDM) is an excellent method of surface modification of biomaterials. The EDM method can change the microstructure and deposit bioactive materials on the surfaces simultaneously to improve biological responses by increasing MRR, microhardness, wear resistance, corrosion resistance, and surface roughness. Additionally, surface modification through EDM enhanced the biocompatibility and adhesions of host cells. The main aim of this work, the one-variable-at-a-time (OVAT) method, is to evaluate the effective range of EDM process parameters for AZ31BMg on responses like material removal rate (MRR), surface roughness (SR), and dimensional deviation (DD). Experimentally, it is observed that the range of CP 2–6 A, Ton 150–250 µs, Toff 50–150 µs, SV 40–60 V, Pc 4–6 g/l, and cryogenically treated electrodes notably influences the response parameters.