A simple synthetic model of the single scattering properties of the atmospheric Martian dust suitable for radiative transfer calculations in the infrared is presented. The model is built by modifying the long-standing Toon et al. [1977> model in order to reproduce accurately the Mariner 9 observations of the 1971 dust storm, without concern to the actual dust composition. Compared to previous Martian dust models which were based on known Earth-analog material, this model should allow more accurate radiative transfer calculations, until new data from the upcoming spacecraft missions becomes available. Integrated values suitable for broad-band climate models are also provided. ¿ 1998 American Geophysical Union