The dielectric continuum model of longitudinal‐optical phonons in polar semiconductors is used to define the role of interface longitudinal‐optical phonons in affecting phonon‐assisted &Ggr;–Xtransitions in GaAs–AlAs and GaAs–GaP superlattices. In particular, the dielectric continuum model for interface optical phonons is used in conjunction with a Kronig–Penney model of the superlattice electronic properties for two purposes: to specify superlattice parameters where interface‐phonon‐assisted &Ggr;–Xtransitions are expected and to estimate relative transition probability amplitudes for interface‐phonon‐assisted &Ggr;–Xtransitions in selected short‐period superlattices.