The phonon dynamics of the spin-ladder vanadium oxides AV(2)O(5) (A=Na,Ca,Mg,Cs) is studied using infrared and Raman spectroscopy techniques. The infrared-active phonon frequencies are obtained by Kramers-Kronig analysis of the reflectivity data. The assignment of the phonon modes in (Ca,Mg,Cs)V2O5 is based on the shell model lattice dynamical calculation of alpha(')-NaV2O5. The large phonon frequency (448 cm(-1)) renormalization in the sodium-deficient samples is found to be similar to the resonant-induced phonon renormalization in the nominally pure alpha(')-NaV2O5. In the Raman spectra of CaV2O5 and MgV2O5 we observed the phonon overtones and combinational lines up to the fourth order. No spin-related modes are found in CsV2O5.