The use of light scattering for studying the structure of polycrystalline polymer films has been described by this and other laboratories (1–3). Theory and experimental methods for photographically and photometrically studying the scattering of films have been described. In this paper, currently used techniques and procedures for measuring the scattering of both films and fibers are described, and methods for separating contributions to scattering from density and orientation heterogeneities and voids are proposed. Procedures are given for determining uniaxial and biaxial orientation of superstructure, as are methods for estimating sizes and anisotropy of structure.