Bis(trifluoromethylthio)ketene (CF3S)2C=C=O has been synthesized by dehydration of (CF3S)2CHC(O)OH or HCl elimination from (CF3S)2CHC(O)Cl and fully characterized. Some reactions of the ketene are presented. Bis(trifluoromethylthio)ketene (CF3S)2C=C=O has been synthesized by dehydration of (CF3S)2CHC(O)OH or HCl elimination from (CF3S)2CHC(O)Cl and fully characterized. Some reactions of the ketene are presented.