Multiple scattering effects on signals from space lidar are significant and must be accounted for in the retreival of aerosol and cloud extinction. It is shown that a simple parameterization of multiple scattering allows one to account for multiple scattering effects using a slightly modified form of a commonly used single-scatter retrieval solution. All orders of scattering are considered in the development of parameterizaiton appropriate for the CALIPSO lidar. Applications to aerosol and cloud retreivals are discussed.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.