In the present work, polanga oil has been used as the bio-dielectric for the machining of P20 steel by the electro-discharge machining (EDM) process with a tool made up of pure copper. As the pure polanga oil has a high viscosity (72cSt at 40 ℃), it has been chemically processed to make it suitable to be used as a dielectric fluid. The process parameters, viz. sparking current, pulse ON time (Ton) and pulse OFF time (Toff) have been used to investigate the EDM process. The material removal rate (MRR) and surface roughness (Ra) have been considered to evaluate the EDM process. The experiments were conducted using bio-dielectric polanga oil as well as the conventional dielectric fluid, i.e., kerosene. It has been observed that the MRR is improved by 0.08–0.77 times when machined with polanga oil as the dielectric. However, no significant improvement is observed in the surface finish when polanga oil is used as a dielectric.