Hyper-Rayleigh scattering (HRS) is the only second-order nonlinear optical (NLO) technique allowed in an isotropic solution. Being an even-order technique, it is sensitive to (non-centro)symmetry. Therefore, HRS is a unique tool to determine solution-phase structure, both in a qualitative and a quantitative way. Examples are presented of the elucidation of the actual D2d octopolar structure of highly symmetric, yet non-centrosymmetric chromophores and of the determination of the value for the opening angle of a chromophore-functionalized alkynyl-calix[4]arene cavity.