The present work focused on the selective sorption of silver ions from aqueous solutions by a thiourea-grafted mesoporous polystyrene resin and subsequent reduction of the Ag+ ions to silver nanopartides (AgNPs) embedded in the polymer matrix. The effects of various parameters such as pH, contact time, concentration, temperature, and presence of competing metal ions were studied for the optimum uptake of silver ions to enhance the yield of AgNPs. The most favorable sorption of silver ions was observed in the pH range of 1.5-1.0 and at 27-30 degrees C. A chemical method was used for in situ reduction of the adsorbed silver ions to AgNPs on the polymer matrix. The polymer-embedded AgNPs showed a very good bactericidal activity against Escherichia coli. The AgNPs were separated from the polymer support by ultrasonication and characterized by TEM, UV-vis spectroscopy, EDX, and XRD. The particles were of cubic phase (fcc) and were monodispersed with a mean diameter of 8 nm.