Binary and ternary mixtures of molten salt nitrates (LiNO3 -NaNO3 and KNO3) are ideal candidates as large scale phase change thermal energy storage materials and as heat transfer fluids for concentrating solar power systems. They have higher specific heat capacities and wider operating temperature ranges (150-600°C) compared to the silicon based oils which are currently used in parabolic trough type plants. For design considerations related to power plant and equipment, it is critically important to know the thermo-physical properties of molten salt nitrates, as thermal conductivity being one of the most important. In this regard, the measurements of thermal conductivity of molten salt nitrates are of interest in the present study.