Local infectious diseases are disorders caused by a pathogen such as bacteria, fungi, virus, and protozoa that commonly occur in the eyes, oral cavity, bone, and skin. Recently, the general treatments for most local infections are systemic antibiotic, including oral and intravenous administrations, which possess numerous side effects, limited efficacy, and increased risks of antibiotic resistance. To overcome these drawbacks, local drug delivery systems demonstrate much potentials. One of these interesting systems is nanoparticles-hydrogel composites, which is the smart incorporation of antimicrobial-nanoparticles (i.e., Ag/Au nanoparticles, drugloaded nanoparticles) into the hydrogel matrix. This approach yields double benefits of the nanoparticles controlled drug release property and the hydrogel mucoadhesiveness with long retention time property. To that end, this review focuses on nanoparticles-hydrogel composites for local antimicrobial treatments. The review firstly states the definitions and types of nanoparticles-hydrogel composites. Then, the system preparation methods and physicochemical characterization tests are presented. Next, the applications of nanoparticleshydrogel composites on local infections are thoroughly discussed, focused on five main areas of the eyes, oral cavity, bone, skin, and healthcare-associated infections. Finally, the challenges and future prospects of research in this field are considered.