The satellite thermal control maintains temperatures of all satellite components within their allowable operational temperature limits, throughout the satellite mission. Aluminum and composite materials are used for satellite structures. Thermal control performance, structural properties and manufacturing cost are important factors in selection of satellite structures. In this paper, we present the comparison of thermal performance of aluminum and composites, used as structural materials for a small satellite. We have also studied the effect of thermal contact resistance, between the satellite main components and the structural elements, on the overall thermal performance of these satellite structures. The temperature results, for major satellite components in the two types of structures considered in this paper, show the improvement in the overall thermal performance of composite satellite structures over the aluminum satellite structure.