<p>Chitosan (CT)-functionalized metal nanoparticles have emerged as a versatile class of antimicrobial agents, combining the inherent biological activity, biodegradability, and biocompatibility of CT with the broad-spectrum antimicrobial potential of metallic nanostructures. In recent years, substantial progress has been achieved in their design, synthesis, and application to address the global challenge of pathogenic microorganisms, including multidrug-resistant (MDR) bacteria and fungi. Advances in green synthesis techniques, surface engineering, and hybrid composite formation have not only enhanced nanoparticle stability and dispersion but also enabled synergistic antimicrobial mechanisms such as electrostatic interactions with microbial membranes, cell wall disruption, and reactive oxygen species (ROS) generation. Beyond their bactericidal and fungicidal properties, CT-functionalized metal nanoparticles have demonstrated efficacy in inhibiting biofilm formation, accelerating wound healing, and extending shelf life in food preservation, making them highly relevant for biomedical, environmental, and industrial applications. This review summarizes trends in chitosan-functionalized metal nanoparticles (2022–2025), focusing on novel synthesis methods, structure-function relationships, and antimicrobial mechanisms. It highlights advances in green fabrication, the role of chitosan in enhancing stability, activity, and safety, and compares the performance of different metals. We hope this work will assist researchers in advancing this field.</p> Graphical abstract <p></p>