The reaction of trifluoromethylthiocopper with halomethanes, namely di- and triiodo-, dibromodichloro-, dibromochlorofluoro-, dibromo-difluoro-,bromochlorofluoro-, phenyltrichloro-, bromocyano- and dibromofluoro-methanes, has been investigated in detail. In addition to the expected compounds, the formation of unusual products such as bis(trifluoromethyl)trithiocarbonate, dimethyl(trifluoromethylthio)benzene