A laboratory study was conducted to evaluate the possibility of immobilizing spent ion exchange resins using geopolymer process that was prepared at room temperature. The main objective of this research is to determine the suitability of using geopolymer in radioactive waste immobilization. The spent ion exchange resins and fly ash were obtained from PUSPATI TRIGA Reactor and Sultan Salahuddin Abdul Aziz Power Plant, Kapar, Selangor respectively. The geopolymer was activated with NaOH and Na2SO3 at room temperature. Gamma spectrometry analysis indicated the presence of 40K, 226Ra and 232Th in fly ash while in spent ion exchange resins showed the presence of activation and fission products i.e. 134Cs, 137Cs, 152Eu, 54Mn, 58Co, 60Co and 65Zn. The composition of the materials that made up the monolith was 10% (wt) of spent ion exchange resin, with a compressive strength of 6.1 MPa. The leaching rates of the radionuclides were used as indicators of immobilization performance of the solidified waste forms. The leaching test shows different leaching rates of 134Cs, 137Cs, 226Ra, 60Co and 40K from the monolith geopolymer. The results show that immobilization of spent ion exchange resins using fly ash based geopolymer significantly affect the leaching rate of the radionuclides. This finding could in future benefits the treatment of low level and intermediate waste generated from nuclear power plant operation.