Silver nanoparticles (AgNPs) was evaluated  for its possible effects on the incidence of seed rot disease of Faba bean, Tomato and Barley caused by the seed and soil borne fungus Fusarium oxysporium. The Silver nanoparticles were biosynthesized by the fungus Trichoderma longibrachiatum and characterized by UV-Visible (UV-Vis) spectroscopy, Transmission Electron Microscope (TEM) and Dynamic Light Scattering (DLS) (Raid, 2013). Silver nanoparticles characterized as spherical shape, almost monodispersed at size of 1-20 nm. A preliminary study also performed in order to find out its suspected toxic effects, using different concentrations of Silver nanoparticles solutions on germination, vigour index and on the Fusarium oxysporium infection on the target crops. Silver nitrate solution or water treatment was used as positive and negative control respectively. Healthy and infected seeds were soaked in three different concentrations of Silver nanoparticles (0.5, 0.25 and 0.12 mM). At the higher concentration, silver nanoparticles alone or in combination with Fusarium spores showed adverse effect on seed germination and vigour index. The lower concentration of silver nanoparticles improved the seed germination percentage and vigour index, in addition to reduce the disease incidence (seed rot disease) caused by Fusarium oxysporium. The higher concentration of Silver nanoparticles 0.5 mM showed a slightly effects on seed germination percentage and vigour index in tomato seedlings. Silver nanoparticles at concentration of 0.12 mM were less toxic to the tomato, faba bean and barley seedlings. It also reduced the disease incidence. Therefore, it is recommended to consider Silver nanoparticles in further studies for possible controlling of seed-borne pathogens putting in mind its possible accumulation in the crop products and the consecutive in food chain.