Chitosan (CS) and chitosan nanoparticles (CS/NPs) were prepared from shrimp and crab wastes and they were characterized using spectral analysis, Fourier transforms infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Energy Dispersive analysis of X-Ray and Spectroscopy (EDAX) analysis. Also, functional and physicochemical properties of the extracted chitosan and chitosan nanoparticles were analysed. The morphological properties of chitosan and its nanoparticles revealed a smooth surface and fibrous structures with pores. Crab chitosan and its nanoparticles had the highest values of moisture (6.13 and 6.20%) and ash contents (2.60 and 2.90%), respectively. While the highest value of nitrogen (8.50%) was found in commercial chitosan. The highest extraction yield (16.33%) was recorded for crab chitosan compared with (15.35%) for shrimp chitosan. Water binding capacity was higher (780-782%) in shrimp chitosan and its nanoparticles, whereas commercial chitosan and its nanoparticles recorded the highest values (539-539%) fat binding capacity. On the other hand, shrimp chitosan and its nano-type recorded the highest degrees of deacetylation values 92% and 90%, respectively. The solubility was proportional to the degree of deacetylation. The results revealed that chitosan nanoparticles process improved the physicochemical, functional, and morphological characteristics of the extracted chitosan.