The present study was designed to investigate the antifungal potential of methanolic leaf extracts of Acacia nilotica extracts against Aspergillus fumigatus, a common fungal pathogen known for causing various postharvest diseases. In this study, methanolic leaf extract was prepared using standard extraction methods and its antifungal activity was evaluated through liquid broth assay. For that, four treatments viz. 2%, 4%, 6% and 8% of the leaf extract were prepared in 2% malt extract broth. After autoclaving, the fungal suspension was inoculated in the prepared methanolic extract containing medium. After seven days of incubation growth of mycelium (fresh and dry weight) and antioxidant enzyme (peroxidase and catalase) activities were estimated. Results revealed significant (P≤0.05) antifungal activity of A. nilotica methanolic leaf extracts against A. fumigatus, with decreasing mycelial growth up to 99% in comparison with control. The results indicated effective inhibition of fungal growth at relatively low concentrations of the leaf extracts. Additionally, the study explored that the enzyme activities of tested fungi was significantly increased by 2 folds as compared to control. Overall, the findings suggest that native A. nilotica possesses promising antifungal properties against A. fumigatus, highlighting its potential as a natural source of antifungal agents for combating fungal infections.