A new durable antibacterial cotton fabric was successfully prepared by free-radical graft copolymerization of acrylic acid (AA) and itaconic acid (IA) onto a cotton fabric in an aqueous medium. Ammonium persulfate (APS) was used as the initiator in the presence of a crosslinker, methylene bisacrylamide (MBA). The nanocomposite hydrogel was obtained from in situ formation of silver nanoparticles from reduction of silver cations by sodium borohydride. A proposed mechanism for nanocomposite formation was suggested and the effect of ratio of IA to AA on water absorbency discussed. FTIR, UV-Vis, X-ray, and scanning electron microscopy were employed to characterize the structure of the prepared superabsorbent. The antibacterial activity of the hydrogel was tested qualitatively and quantitatively. Results showed that the silver nanoparticle-loaded fabric has potent antibacterial activity to Escherichia coli Gram-negative bacteria.