Here we present a facile and simple in-situ method for the preparation of poly(acrylic acid)-silver nanocomposite thin films with highly dispersed silver nanoparticles. From the various available methods to reduce Ag+ silver ions, the chemical method was chosen to generate silver nanoparticles in a poly(acrylic acid) matrix. The reducing reagent used in this study was the primary diamine, polyoxypropylenediamine, which reduced the silver ions and simultaneously hardened the poly(acrylic acid) via a cross-linking reaction. TEM images showed that the silver nanoparticles were well dispersed in the poly(acrylic acid) matrix condensed with polyoxypropylenediamine.