Dendrimers have been used as a vehicle to develop the antimicrobial properties of textile fabrics. We have taken advantage of the large number of functional groups present in the regular and highly branched three-dimensional architecture of dendrimers. In this study, the poly(amidoamine) (PAMAM) G-3 dendrimer was modified to provide antimicrobial properties. Following a procedure similar to what is suggested in the literature, PAMAM (G3) with primary amine end groups was converted into ammonium functionalities. The modification was then confirmed by FTIR and C-13-NMR analysis. Dendrimers have unique properties owing to their globular shape and tunable cavities, this allows them to form complexes with a variety of ions and compounds; and also act as a template to fabricate metal nanoparticles. AgNO3-PAMAM (G3) complex as well as a MesoSilver-PAMAM (G3) complex were formed and these modified dendrimers were characterized by a UV-Visible spectrophotometer to study the complex formation. Modified dendrimers were applied to the Cotton/Nylon blend fabric. SEM and EDX analysis were performed to study the dispersion of silver nanoparticles onto the fabric. An antimicrobial test of the treated-fabric against Staphylococcus aureus exhibited significant biocidal activities for each type of modified-dendrimer. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115: 716-722, 2010