Numerical calculations of the circular intensity differential scattering of light by oriented helical structures made of units with general polarizability tensors are presented. The effects on the scattering patterns of both absorptive and dispersive properties of the units are illustrated. The differential scattering and the total scattering both show anomalous scattering phenomena; the differential scattering pattern is asymmetric when the wavelength of incident light is within an absorption band. Equations for biaxial polarizabilities are used to derive the symmetry properties of the differential scattering pattern and to show how this symmetry can be used to determine the right- or left-handed sense of the helical structure. The wave-length dependence of the scattering pattern is obtained for a Lorentzian polarizability. © 1981 American Institute of Physics.