Gold nanoparticles (Au NPs) possess unique properties for research due to their high stability and catalytic activity in electron transfer processes, such as hydrogenation reactions. One of the major challenges for application of Au NPs in heterogeneous catalysis is the search for better support materials to further increase their stability and catalytic activity. In this study, Au NPs were generated in the nanochannels of poly (acrylic acid) grafted poly (ethylene terephthalate) track-etched membranes (PAA-g-PET TeMs) by radiation-induced reduction in alcoholic solution using electron beams (5 MeV) and gamma-radiation (Co-60). Prior to irradiation Au3+ ions were immobilized by carboxylate groups of PAA grafts on PET TeMs. The effect of the absorbed dose as well as dose rate on the size and other characteristics of Au NPs were studied using UV-vis, FTIR, XPS spectroscopies, SEM and XRD analysis. It was found that PAA-g-PET TeMs can be successfully used as support material for radiation-induced synthesis of Au NPs with different sizes. The catalytic activity was investigated with the reduction of 4-nitrophenol. The catalytic activity depends on the size of Au NPs, 10-20 nm Au NPs (synthesized using e-beam) showed first order reaction rate constant of 0.048 min(-1), and for 20-35 nm (synthesized using gamma-rays) of 0.023 min(-1). Thus for the first time, Au NPs were successfully obtained on modified PET TeMs showing high potential for catalytic applications.