The potential antifungal activity of seed storage glycoprotein (7S globulin) isolated from Cowpea and Lupin seeds against the pathogenic fungus Pythium sp. that cause fruit rot in cucumber was tested in vitro and in vivo on cucumber fruits after the harvesting compared to control. The 7S globulin obtained from Cowpea had a high content of total amino acid (78.2%) against 77.27% for 7S globulin obtained from Lupin. Both protein fractions have similar electrophoretic patterns despite different band locations on the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The pathogen was identified in the Plant Pathology Department Lab., Faculty of Agriculture, Zagazig University, as Pythium sp. The mycelial growth of Pythium sp. in liquid media was evidently reduced in the presence of 7S globulin from Cowpea and Lupin in a concentrationdependent manner. The application of 500 µg/mL 7S globulin entirely destabilized and deformed this shape in both compounds (Lupin seed 7S and Cowpea seed 7S). Scanning electron microscopy (SEM) images of the mycelium of Pythium. sp. in inhibition zones induced by either Lupin 7S or Cowpea 7S revealed significant morphological changes in the hyphae, including deformation and contraction. The in vivo tests showed that both Cowpea 7S globulin and Lupine 7S globulin effectively reduced the incidence of postharvest Pythium. sp. infection on cucumber fruits. It can be concluded that there are indeed alternatives to replace the synthetic fungicides for the management of this notorious soil as well as seed-borne fungi (Pythium), which causes big agricultural losses.