The recovery of actinides such as U(VI) and Th(IV) from nuclear waste is a critical challenge and it requires the development of novel selective and high-capacity sequestering materials. Herein a novel chelating adsorbents are prepared by grafting poly(amido)amine (PAMAM) and diglycolamic acid (DGA) functionalized PAMAM dendron on styrene divinyl benzene (SDB) solid support. Adsorption of U(VI) and Th(IV) from simulated nuclear liquid waste (SNLW) using PAMAM–SDB and DGA–PAMAM–SDB chelating resins were carried out. Our studies have found that PAMAM–SDB and DGA–PAMAM–SDB chelating resins exhibited good adsorption selectivity for U(VI) and Th(IV) at pH 5.5 in presence of other metal ions. In addition, these chelating resins finds potential application for total decontamination of SNLW at pH 12. Hence, PAMAM–SDB and DGA–PAMAM–SDB are promising chelating resins for selective removal of U(VI) and Th(IV) and also total decontamination of aqueous radioactive waste. © 2019, Institute of Chemistry, Slovak Academy of Sciences.