The ability of crown-ethers for selective separation in a few cases is well known. Initial experiments were made to investigate the stability against gamma-irradiation. In tltese experiments l8-crown-6-ethers were used. Irradiation was carried out in the dose range from 5 kGy up to 1 MGy using a60Co-source. Radiolysis products were analyzed by gas chromatography andNMR-spectroscopy. It has been shown that crown-ethers can be used for separation steps in various radiochemical processes not only in a laboratory but also in a technical scale.