The goal of this study was to look into the antifungal properties of the leaves, stem, and roots of Cassia angustifolia Vahl. and effect of different climatic conditions on the activity. The root, stem, and leaves of the ethnomedicinal plant Cassia angustifolia Vahl. collected from Rajasthan, Gujrat, and Tamilnadu districts of India were extracted using chloroform, acetone, and petroleum ether and these extracts were evaluated for their antifungal potential against four fungi Aletrnaria alternata, Sclerotinia sclerotiorum, Fusarium oxysporum, and Penicillium notatum by agar disc diffusion method. The antifungal potentials of extracts were compared to that of regular ketoconazole in terms of zone of inhibition. The results demonstrated a notable suppression of fungal growth of the selected fungi by the plant extracts. In terms of Minimal Inhibitory Concentration (MIC) (g/ml), the antifungal activity of various plant components ranged from 6.5 to 400 g/ml. The plants' phytochemical compositions were examined. The presence of different secondary metabolites contributed to the Cassia angustifolia's microbial activity. Pet ether extract of the stem from Rajasthan showed the lowest MIC value against Alternaria alternata (15 mg/L) and Pet ether extract of the stem from Tamilnadu showed the lowest MIC value against Sclerotinia sclerotiorum (25 mg/L). Acetone extract of the root from Gujrat showed the lowest MIC value (6.25 mg/L) against Penicillum notatum while chloroform extract of the leaves from Tamilnadu showed the lowest MIC value (25 mg/L) against Fusarium oxysporum. Results revealed that antifungal activity of the plant was also affected by climatic conditions.