[Me4N]+[SO2F3]−, the first example of a [SO2F3]− salt, has been prepared from Me4NF and SO2F2. The colorless, microcrystalline solid was characterized by its infrared and Raman spectra. The trigonal bipyramidal structure of C2v symmetry of the [SO2F3]− anion is predicted by ab initio calculations. Two oxygen atoms with d(SO)=143.2 pm and one fluorine atom with d(SF)=157.9 pm occupy the equatorial plane. The two fluorine atoms in the axial position with d(SF)=168.5 pm are repulsed by the two oxygen atoms forming a bent axis with ∡(FaxSFax)=165.2°.