The present study aims to investigates the impact of Camphor Oil on the pathogenic fungus Macrophomina phaseolina using the Poisoned Food Technique. Macrophomina phaseolina is a destructive phytopathogen responsible for causing various crop diseases, leading to significant agricultural losses. Camphor Oil, derived from the camphor tree, possesses potential antifungal properties and has been explored as a natural alternative to chemical fungicides. The study aimed to assess the inhibitory effects of Camphor Oil on the growth and development of Macrophomina phaseolina in a laboratory setting. The Poisoned Food Technique was employed to evaluate the antifungal activity of different concentrations of camphor oil viz., 20%, 40%, 60%, 80% and 100% on Macrophomina phaseolina isolated from watermelon (Citrullus lanatus) seeds. The results revealed that Camphor oil is not effective against Macrophomina phaseolina leading to the conclusion that Macrophomina phaseolina is a strong devastating plant pathogen which is resistant to natural products such as camphor oil. Further studies should be carried out to investigate the effect of other natural products against Macrophomina phaseolina.