This chapter explores the phenomenon of light scattering from dilute polymer solutions. Light scattering is an important experimental technique for polymers for several reasons. Scattering is the reradiation of a traveling wave due to a change in the character of the medium in which the wave is propagating. For light, scattering will be caused by local changes in refractive index or polarizability due to, for example, a dust particle in the air or a polymer in the solvent. The typical light source is a laser, although the unique features of a laser source (e.g., temporal and spatial coherence, collimation, high monochromaticity) are not required. The most desirable feature of the source is stability. In routine applications it is usually assumed that the scattered light is entirely polarized vertically (for vertically polarized incident light), and a polarizer is not used in front of the detector. Light scattering is a very powerful experimental tool, providing both thermodynamic and structural information.