The extraction of ⁹⁰Sr and ⁹⁰Y from alkaline carbonate media with tetrachloroethylene solutions of p-tert-butyl and p-isononylcalix[8]arenes with various substituents in the lower rim was studied. The dependences of the ⁹⁰Sr and ⁹⁰Y distribution ratios on pH of the aqueous phase in the interval from 11 to 14 were studied. Among the calixarenes tested, p-alkylcalix[8]arenes with a bridging group in the lower rim show the highest performance in the extraction of ⁹⁰Sr and ⁹⁰Y.