The PF(3)H(+)ion is prepared as PF3H+. SbF6- HF by protonation of PF3 with HF/SbF5 at low temperatures in anhydrous HF. Crystals are obtained directly from this solvent. A crystal structure determination shows the presence of a pseudo-tetrahedral PF3H+ ion with a mean P-F distance of 148.7(2) pm, a P-H distance of 122(4) pm, and a mean PF2 angle of 106.1(1)degrees. Raman spectra were recorded of PF3H+SbF6-. HF and PF3D+ SbF6-. DF and assigned with the help of ab initio calculations. AsF3 does not react with HF/SbF5, whereas SF4 forms SF3+SbF6-. HF, which is isostructural with PF3H+SbF6-. HF.