Chitosan (CS) is a derivative of chitin and is a biocompatible polysaccharide that is composed of 2-amino-2-deoxy-â-D-glucan monomers. Due to its capacity to form interactions with polyanions, CS has been widely used in various studies to prepare chitosan nanoparticles (CNP) for potential applications as delivery systems for therapeutic agents. However, research done on antibacterial potencies of CNP and CNP loaded with metal ions has been limited. In the present study CNP, CNP loaded with copper ions (Cu-CNP), and CNP loaded with silver ions (Ag-CNP) were prepared and studied. Three different grades (molar mass) of CS were used to prepare CNP and CNP enhanced with metal ions. Copper sulfate was used as source of Cu2+ and silver nitrate was used as source of Ag+. The nanoparticles were characterized by scanning electron microscopy (SEM) and the metal content was determined by electrodeposition (for Cu2+) and titration (for Ag+). The antibacterial properties of CNP and metal enhanced-CNP were tested against Gram negative and Gram positive bacteria. CNP showed increased antibacterial activity compared to CS and positive coaction with the metal cations.