In this paper the polyphenolic compounds of methanolic extract of Jatropha curcas leaves have been investigated. The analytical procedures revealed 7 flavonoid compounds:  biapigenin-(8,8″)-methylene-6,6″-di-C-β-D-glucopyranoside (1), apigenin-7-O-β-D-neohesperidoside (2), apigenin 7-O-β-D-galactoside (3), orientin (4), apigenin (5), isovitexin (6) and vitexin (7). The crude methanol extract and the 7 purified compounds were tested against fungi Botrytis cinerea, Rhizoctonia solani, Sclerotinia sclerotiorum and Fusarium solani. The crude extracts absolutely inhibit the fungi growth. On the other hand, vitexin was similar to crude extract as well. The other compounds were moderate in their antifungal effects in comparison to control ones. In-vitro antimicrobial activity of the methanolic leaves extract was carried out by using the agar-well diffusion method on Gram-positive bacteria Staphylococcus aureus. The Gram-negative included Escherichia coli was compared with standard drug Streptomycin and Ampicillin.