Wounds are the ideal setting for the development of micro-organisms, so it is often necessary to apply a dressing to control bacterial colonization. Cotton is commonly used in dressings, as it exhibits important hydrophilic characteristics such as high moisture and fluid retention properties, but it may provide a sustainable media for the development of micro-organisms. In this way, the development of new strategies to provide cotton materials with lasting and effective antimicrobial properties is of the utmost importance. Consequently, here we described two processes to develop cotton-dressings functionalized with antimicrobial peptides (AMPs) magainin I (MagI) and LL-37, in order to give cotton-dressings an antibacterial effect. The AMPs showed no cytotoxic effect against human fibroblasts so they are safe to contact with skin. In addition, the functionalized materials with either LL-37 or MagI present an antimicrobial effect exhibiting inhibition ratios of 89% against Klebsiella pneumoniae and 58% against Staphylococcus aureus, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40997.