This chapter reviews how the polarization of light scattered by interplanetary dust has been used to determine some physical properties of the dust population in the interplanetary medium. Though optically thin, the interplanetary dust cloud is visible due to the faint glow (the zodiacal light) it produces at visible wavelengths through the scattering of light from the Sun by interplanetary dust particles (IDPs). The light, scattered by an optically thin medium is linearly polarized, with the E-vector predominantly oscillating perpendicular or parallel to the scattering plane, leading to negative values of the degree of linear polarization, PQ, in the backscattering region. The zodiacal light also has an IR component, due to the thermal emission from the dust particles, whose characteristics are consistent with the conclusions from the polarimetry. While some results from intensity observations are used for discussion in this chapter, complete reviews of the zodiacal light intensity studies can be found in Leinert et al. (1998) and Levasseur-Regourd et al. (2001). Sections 24.1 and 24.2 summarize the zodiacal light photopolarimetric observations, going from the whole line-of-sight integrated values to the local values retrieved by inversion. Sections 24.3 and 24.4 explain how numerical simulations and laboratory experiments have been carried out to constrain the interplanetary dust properties at different locations in the cloud based on their polarimetric signatures.