This book explores the impact of chitosan nanoparticles on plants under various stress conditions. The book highlights the versatility and efficacy of chitosan nanoparticles as a stress-alleviating agent, emphasizing their role in improving plant health and productivity. It reveals all possible features that chitosan nanoparticles might bear as a stress-alleviating agent, underlining their role in promoting plant health and productivity. This book highlights the molecular and physiological pathways through which a response brought by chitosan nanoparticles occurs and sheds light on their mode of action. In it, issues such as control over oxidative stress, modulation of hormones, and gene expression are thoroughly discussed in a manner that provides a complete understanding of how chitosan nanoparticles improve plant resilience. The information is important in the development of specific, targeted approaches to solving particular agricultural problems. Beyond this, this book reviews the applications of chitosan nanoparticles within the scope of foliar spray, soil treatment, and seed dressing. This book aims to serve as a valuable resource for researchers, students, and practitioners seeking to harness the potential of chitosan nanoparticles in agriculture. Addressing current challenges and future opportunities pave the way for the development and adoption of innovative technologies that contribute to global food security and environmental sustainability. This book features contributions from leading researchers and professionals in the fields of plant science, nanotechnology, and agricultural sustainability, ensuring a multidisciplinary perspective.