We summarize the status of the scattering of scalar waves from random surfaces for both coherent and incoherent applications. The usual surface descriptor is via a Gaussian probability distribution in height and, for homogeneous statistics, a correlation function (or its Fourier transform, the surface spectral function). For isotropic surfaces, this leads to a parametric surface description in terms of two independent dimensionless length scales involving wavelength, surface rms height, and correlation distance. For coherent scattering, Kirchoff and perturbation methods are valid for only small roughness. Integral equation methods (Dyson equation} extend the range of validity to larger roughness but further extensions face computability problems. Applications include long range propagation in waveguides with rough walls. Incoherent scattering is described using a Bethe‐Salpeter formalism which requires extensive approximations to be tractable. Some comparison with experiment will be given as well as a brief discussion of recent developments.