Bioactive packaging is a term that has become increasingly widespread in society. This packaging enhances the effectiveness against food deterioration and inhibiting microbial growth, which is often associated with food loss and waste (1). Natural extracts from agro-industrial by-products have been shown to improve packaging properties, including physical and mechanical characteristics, while also potentially providing antioxidant and antimicrobial effects. Which can extend food shelf life and reduce dependence on synthetic additives (2). This research focuses on Castanea sativa hedgehog extracts obtained from northeastern Portugal. This by-product extract is rich in bioactive components, including both condensed and hydrolysable tannins, phenolic acids (such as ellagic and gallic acids), and flavonoids (including catechin, epicatechin, apigenin, quercetin, and rutin), all of which exhibit important antioxidant and antimicrobial activities (3,4). The purpose of this study is to evaluate the possibility of incorporating C. sativa hedgehog extracts as bioactive compounds in composite films. The biological properties of this extract, such as its antibiofilm, antimicrobial, and antioxidant characteristics, were assessed. The results obtained show high antioxidant activity, with free radical scavenging values of 0.17 mMTrolox/g and 0.43 mMTrolox/g, as determined by the Ferric Reducing Antioxidant Power and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) assays, respectively. In terms of antimicrobial assays against key pathogens, the extracts demonstrated broad-spectrum efficacy, achieving activity rates of 78% against Staphylococcus aureus, 75% against Escherichia coli, and 51% against Klebsiella pneumoniae. Furthermore, biofilm reduction was observed, with decreases of 75% for S. aureus, 54% for E. coli, and 36% for K. pneumoniae. These results support the statement that C. sativa hedgehog extracts represent a promising natural source of bioactive compounds for future applications in bioactive packaging materials.