This paper presents a method for the preparation of silver nano-particles in poly (diallyldimethylammonium chloride) (PDDA) using N,N-dimethylformamide (DMF) as a medium has been performed successfully. A golden solution in its UV-vis absorption spectrum showed surface plasmon resonance absorption bands between 410 and 425 nm in solutions and at about 461 nm in a transparent film. The Ag/PDDA nano-composite was characterized by X-ray diffraction (XRD) measurement, transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform-infrared spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA). XRD showed the fcc crystal structure of the bulk Ag with particles of <22 nm in size similar to that is observed by TEM and PDDA is crucial to the formation of such silver nano-composite. SEM indicated uniform distribution of particles in the film. TGA confirmed enhanced thermal stability of the polymer. (C) 2011 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.