N-vinyl 2-pyrrolidone (VP) / Acrylonitrile (AN) copolymeric hydrogels were synthesized by using gamma-radiation and amidoximated for the purpose of uranyl ion adsorption. Optimum amidoximation time was determined by following the uranyl ion, UO22+, adsorption capacity. The adsorption of amidoximated copolymers was studied from different uranyl ion solutions (1000-1850 ppm). The results of all adsorption studies showed that the interaction between UO22+ and amidoxime groups comply with Langmuir type isotherm. The adsorption capacity was found as 0.54 g UO22+ /g dry amidoximated copolymeric hydrogels. From the stoichiometric calculations, it was found that the bonding between UO22+ and amidoxime groups is I to 4.