For negatively curved symmetric spaces such as real hyperbolic spaces scattering matrices are defined via the standard intertwining operators for the spherical principal representations of the isometry group. They depend meromorphically on spectral parameters and it is known that their poles are either given as poles of the intertwining operators or as quantum resonances, i.e. poles of the meromorphically continued resolvents of the Laplace-Beltrami operator. In this talk I will explain these facts and discuss extensions to locally symmetric spaces of negative curvature.