Halogenated nucleoside derivatives were trifluoromethylated using a solution of a trifluoromethyl–coppercomplex, which was prepared by shaking trifluoromethyl iodide and copper powder in hexamethylphosphoric triamide and filtering off the excess of copper powder. The following trifluoromethylated nucleosides were obtained in moderate to good yields: 5-trifluoromethyl-uridine, -deoxyuridine, -cytidine