The use of chitin-based nanoparticles in plant disease management has gained significant attention due to their unique properties and potential applications. Chitin, a natural polysaccharide found in the exoskeletons of crustaceans, insects, and fungal cell walls, is a promising material for developing nanoparticles. Different methods can synthesize chitin-based nanoparticles, such as mechanochemical, enzymatic hydrolysis, and ionic liquid-mediated synthesis. The nanoparticles exhibit antifungal and antibacterial properties, making them effective agents against various plant pathogens. Additionally, the biocompatibility and biodegradability of chitin-based nanoparticles make them environmentally friendly alternatives to traditional chemical pesticides. This chapter also discusses how these nanoparticles interact with plant pathogens and enhance plant defense mechanisms. Chitin-based nanoparticles present a promising and sustainable substitute for traditional chemical-based approaches to plant disease management, given their biodegradability, biocompatibility, and non-toxic nature. Consequently, these nanoparticles hold significant potential to transform the landscape of agricultural practices and plant disease management.