This paper describes a simple and facile approach to fabricate well dispersed silver nanoparticles (AgNPs) in poly[N-isopropylacrylamide-co-(sodium acrylate)] hydrogels. The silver nanoparticles formed are spherical in shape with a narrow size distribution in the hydrogel networks in which the nanoparticles are stabilized by the polymer network. Uniformly dispersed silver nanoparticles were obtained with poly[N-isopropylacrylamide-co-(sodium acrylate)] hydrogels, whereas a poly(N-isopropylacrylamide)/poly(sodium acrylate) IPN gel showed aggregated nanoparticles. It is demonstrated that the hydrogel network structure determines the size and shape of the nanoparticles. These particles are more stable in the gel networks compared to other reduction methods. The hydrogel/silver nanohybrids were well characterized by XRD, UV-vis spectrometry, scanning electron microscopy and transmission electron microscopy.