Hydration of KPF6, NaPF6, and LiPF6 has been studied in aqueous solutions by means of FTIR spectra of HDO isotopically diluted in H2O. The difference spectra procedure has been applied, which allowed removal of the contribution of bulk water and thus separation of the spectra of solute-affected HDO. In all cases, a high-wavenumber component band at 2667 cm(-1) is present that corresponds to HDO affected by the PF6- anion, which is known as an extreme structure breaker. The band at ca. 2540 cm(-1) corresponds to HDO affected by all studied cations, and another component band at ca. 2445 cm(-1) is additionally visible in the case of the Li+ cation. The probability distribution functions of interatomic O...O distances for HDO affected by the cations clearly display a lower-distance structure for Li+, contrary to both other cations. The existence of a band situated at 2630 cm(-1) for each of the salts is also significant. Its previous interpretation has been ambiguous. On the basis of our current results and known literature data, we ascribe this band to the outermost hydration sphere of cations, which is possible to detect with IR spectroscopy, which depends on the kind of anion.