The present study was conducted to examine the antifungal efficacy of methanolic seeds extract of Zanthoxylum armatum DC against fungal pathogen Sclerotium rolfsi Sacc. Methanolic seed extract of 50, 25 and 12.5 mg mL^-1 significantly decreased the fresh fungal biomass (61% to 70%). The methanolic extract was subjected to GC-MS analysis that revealed the presence of various phytoconstituents. The predominant compounds identified were n-hexadecanoic acid, constituting 44.07% of total fifteen compounds detected. Following closely was oleic acid with 17.84% peak area. This study concludes that methanolic seed extract of Z. armatum possess strong antifungal potential against S. rolfsii. These compounds may inhibit the growth and reproduction of fungal pathogens. These phytochemicals compounds can act as potential candidates for the development of organic fungicides.