Due to the complexity and large amount of computation time required for full sphericalwave treatments of photoelectron diffraction (PD), most calculations to date have made use of either plane wave scattering or s-emission approximations (or both). In this paper we apply the efficient and relatively simple scattering-matrix formalism of Rehr and Albers to photoelectron diffraction, making explicit the computational steps required to implement a spherical-wave PD calculation for arbitrary initial angular momentum li. Our treatment includes full li + 1 and li -1 interchannel interference within the single-scattering approximation. We apply the method to a prototypical system, a photoemitter and one scatterer, to demonstrate the importance of treating the angular momenta and sphericalwave nature of the photoelectrons correctly, particularly at lower energies. © 1990.