In non-destructive testing, it has been suggested that wavelength or frequency dependent Rayleigh wave scattering coefficients could provide a means of characterising surface defects. Only a few Rayleigh wave scattering problems have analytic solutions and most workers have resorted to numerical techniques [1]. In this paper we present details of a new model that can deal with general surface defect geometries. The scheme is used to model Rayleigh wave scattering from curved corners, steps and slots. The implications of the results for a Rayleigh wave based defect characterisation method are discussed briefly.