The tribromomethansulfonate anion (“tribrate”), [Br₃CSO₃]⁻, has been prepared for the first time. The anion is, up to now, the biggest brother of the well-known triflate anion. Key step of the synthesis is the bromination of phenyl-methanesulfonate by KOBr. The new anion could be investigated in the solid state for the example of K[Br₃CSO₃](H₂O).