Plant pathogenic fungi are one of the most diverse and important groups of microorganisms known to attack a variety of plants. These fungi result in great economic losses, and they also affect large swaths of land and habitats worldwide. Recent research and scientific developments have significantly improved understanding of the disease mechanisms and development of new drugs; however, pathogenic fungi remain a major problem in plants worldwide. Recent developments in nanotechnology have opened new prospects in nanobiotechnology, allowing the development of customized nanoparticles with unique properties and low toxicity. Silver is a precious and economically important metal known for its strong antimicrobial activity. Biologically synthesized silver nanoparticles have recently attracted significant interest because of their potent antimicrobial activity, and several studies have reported the antifungal activity of silver nanoparticles against plant pathogenic fungi. This chapter summarizes the historic and emerging threat of plant pathogenic fungi, and discusses efforts to address present challenges and solutions, particularly biogenic silver nanoparticles, in the control of plant pathogenic fungi.