Abstract We have calculated the phonon dispersion relations of the A15 compound Nb 3 Sb using an angular force model approach, the analysis being restricted to third neighbour interactions only. The force constants have been evaluated by fitting them to the measured values ofphonons at the zone centre. Good agreement has been observed between theory and the available experimental results. It has been inferred that the angular forces are not of significant importance between different atoms (Nb-Sb). The physical aspects for the same are discussed.