The structure of ternary (PbO)x(ZnO)(0.6−x)(P2O5)0.4glasses was investigated using Raman scattering and infrared spectroscopy over the compositional range x = 0–0.6. No significant change of the average chain length composed by PO4 tetrahedral units with the substitution of zinc for the lead cation was observed. The linewidth and wavenumber variations of the Raman high-wavenumber bands reflect the Zn/Pb substitution in these glasses and are correlated with the metal–oxygen force constant and local disorder. The infrared reflectivity spectra have been fitted with the four-parameter dielectric function model. The variation in the 1000–1200 cm−1wavenumber range has been attributed to an increase of the oscillator damping ΓLO(PO3)2− as with PbO content vibrations rather than a variation of the chain length.