This study investigates the biosynthesis of silver nanoparticles by several strains of the fungus *Fusarium oxysporum*. The research demonstrates that aqueous silver ions are reduced in solution by *F. oxysporum* strains, leading to the formation of silver hydrosol with nanoparticles ranging from 20 to 50 nm in size. The reduction process is attributed to a nitrate-dependent reductase and an extracellular electron shuttle involving quinones. The study highlights the potential of this fungal biosynthesis for various technical applications, particularly as antibacterial materials. The efficiency of silver nanoparticle production varies among different *F. oxysporum* strains, influenced by their reductase and quinone generation capabilities. The research also includes methods for characterizing the nanoparticles, such as UV-Vis spectroscopy, fluorescence emission, and scanning electron microscopy (SEM). The findings contribute to the understanding of the mechanisms underlying the biosynthesis of metal nanoparticles by fungi and their potential applications.This study investigates the biosynthesis of silver nanoparticles by several strains of the fungus *Fusarium oxysporum*. The research demonstrates that aqueous silver ions are reduced in solution by *F. oxysporum* strains, leading to the formation of silver hydrosol with nanoparticles ranging from 20 to 50 nm in size. The reduction process is attributed to a nitrate-dependent reductase and an extracellular electron shuttle involving quinones. The study highlights the potential of this fungal biosynthesis for various technical applications, particularly as antibacterial materials. The efficiency of silver nanoparticle production varies among different *F. oxysporum* strains, influenced by their reductase and quinone generation capabilities. The research also includes methods for characterizing the nanoparticles, such as UV-Vis spectroscopy, fluorescence emission, and scanning electron microscopy (SEM). The findings contribute to the understanding of the mechanisms underlying the biosynthesis of metal nanoparticles by fungi and their potential applications.