AbstractYttrium-90 (90Y) has attracted much research attention in targeted radionuclide therapy because its many favorable properties and availability from a long shelf-life generator system. Although numerous generator systems have been developed for the production of 90Y, a common disadvantage is that the 90Y is not eluted in an ionic form suitable for direct labeling of chelating agents bound to useful targeting molecules. In this study, we have adapted previously published procedures and developed a 740 MBq (20 mCi) of generator system in which the parent activity 90Sr was retained on a cation exchange resin, while the daughter 90Y activity was eluted with acetate buffer solution and used directly to label useful radioconjugates without further manipulations. A safety column, not loaded with 90Sr, was connected in series with the generator resulting in an eluate free of any 90Sr breakthrough for at least eight months. The features of this new generator make it suitable for clinical applications.