Postharvest diseases create considerable challenges for agriculture throughout the world; they deprive crop quality and quantity in substantial amount. Chemical treatments and other traditional means for dealing with these pathogens have some downfalls: inundation or contamination of the environment and development of resistant pathogen strains. Emerging nanobiotechnology stands out as promising for these purposes, which is a merging of nanotechnology and biotechnology. This chapter looks into the use of nanomaterials that include the use of nanoparticles, nanobiosensors, and nano-based packaging in postharvest disease management. This involves considerations on mechanisms under which nanomaterials enhance both the detection, prevention, and control of diseases, with emphases on their superior antimicrobial attributes and targeted delivery systems. This chapter highlights the potential use of developing sustainable, effective, and environmentally friendly postharvest management practices by nanotechnology. This chapter also deals with the future prospects and challenges of nanobiotechnology besides establishing the role of regulative frameworks and safety assessments in viewing the way of upholding the great responsibility of utilizing nanomaterials in food systems.