Due to society's growing concern for the environment, there is an increasing demand for developing biomaterials in different industrial sectors. At the governmental level, the application of a circular economy is being promoted, based on the revaluation of by-products produced during manufacturing, which can serve as raw materials for the manufacture of other raw materials. In the past few years, chitosan has come into focus as a potential biomaterial for both the biomedical and food sectors, as it possesses inherent antibacterial and antifungal properties, antioxidant activity, good film-forming abilities, biocompatibility, non-antigenicity, and analgesic, anti-inflammatory and hemostatic activities. Chitosan is a biodegradable polycationic polysaccharide whose main components are glucosamine and N-acetylglucosamine monomers dispersed randomly and connected by β-1,4-glycosidic bonds (Du et al., 2024; Yin et al., 2024). This biopolymer has been studied in different forms, such as nanoemulsions, hydrogels, or composites, obtaining favorable results for its application in edible packaging to help extend the shelf life of perishable foods such as fruits and vegetables, as well as in biomedicine as a material that helps wound healing (Du et al., 2024; Gritsch et al., 2018; Káčerová et al., 2024). Thus, this systematic review aims to present the available information on the formation of antibacterial biomaterials from chitosan with potential applications in biomedicine and food packaging from a circular economy point of view, since this compound is highly present in the skeleton of crustaceans and is a by-product of the food industry.