The vibrational properties of the Al(001)-c(2 × 2)-Na (Li) ordered phases formed by alkali atoms (Na and Li) on the Al(001) surface at low and room temperatures are presented. The equilibrium structural characteristics, phonon dispersions and polarization of vibrational modes as well as the local density of phonon states are calculated using the embedded-atom method. The obtained structural parameters are in close agreement with experimental data.