The lattice dynamics of III–V compounds has been investigated on a 'rigid ion' type of model. The interactions are assumed to consist of Coulomb forces with an effective charge and a general force constant field up to and including second neighbors. Results are presented for the dispersion curves, frequency distribution functions, and effective calorimetric and X-ray Debye temperatures for AlSb, GaP, GaAs, and InSb. The agreement with the experimental data, where available, is reasonable.