Nutraceuticals has a broad range of explication that refers to any food-derived supplement that offers additional health advantages over and beyond the fundamental nutritional content of food. Chitosan is the one among lead compound from chitin, especially acquired from crustacean shells such as prawns or crabs, as also from some fungus cell walls. Advancement in the field of modern technology has curx toward the development of chitosan microparticles subsequently developing chitosan nanoparticles, ensuring the effective use of chitosan in diligence to varying industries. Chitosan nanoparticles poses a prime role due to their potential advantages, including ease of manipulation owing to functional surface groups, easy to surface functionalization, outstanding physicochemical properties, excellent biocompatibility and biodegradability. This chapter discusses chitosan nanoparticles in detail to its intricate physical, chemical, and biological/green methods for the preparation, physicochemical characteristics, different nano-formulations, mainly focusing its nutraceutical applications. In association with recent implementation of green synthesis of chitosan based nutraceuticals poses nontoxic, eco-friendly, and biosafety in production field.