<p>Chitosan as a natural biopolymer derived from chitin has recently attracted significant attention in the field of medical sciences and antimicrobial materials. Chitosan has interesting properties including intrinsic antimicrobial properties, biocompatibility and biodegradability. Recent progress in nanotechnology has led to the development of chitosan-based nanomaterials with significant enhancement of antimicrobial activity including reduction of minimum inhibitory concentrations (MICs) and improvement of biofilm inhibition, for various biomedical applications. This mini-review explores the different antimicrobial mechanisms of chitosan and its derivative and try to highlight recent progress in the design, synthesis and application of chitosan-based nanomaterials against microbial infections. Furthermore, it focuses on different formulation types including nanoparticles, nanofibers and hydrogels for combating microbial infections. Additionally, current challenges and future directions for clinical translation of these nanomaterials are discussed.</p>