Abstract Palladium (Pd) acetate complexes have been incorporated in polysulfone (PS) as a dispersion medium using cosolvent (tetrahydrofuran). The resulting brown-colored [PS-Pd] films of 10–40 wt% complex concentration are thermally stable up to 140°C. Upon incorporation of Pd metal into PS, the glass transition temperatures of the films increase as Pd metal concentration increases. The acetate ligands in [PS-Pd] films are found to be substituted by Cl −1 or CN −1 ligands in aqueous solution. As a result of the relatively easy reduction of Pd(II) in PS to Pd(0), palladium metal particles in various sizes are observed to be formed in PS. The Pd complexes in PS show catalytic activities in hydrogenation of ethylene, CO oxidation and NO reduction by CO or H 2 gases under relatively mild conditions.