Thermal conductivity properties of water-based nanofluids at low concentrations are being presented in this paper. Nanoparticles at low volume concentration in the range of 0.01 to 1% is added to water improve the properties of the base fluid. The properties are estimated at temperatures between 21°C and 45°C. The results indicate an increase of enhancement of thermal conductivity with temperature and are found to be in agreement with different models as well as the data published in the literature. Empirical equations to calculate thermal conductivity and density for varied particle concentration and temperature are established. The measured and predicted values of thermal conductivity and density have a maximum deviation of 8% and 6% in the working range, respectively. © 2012 Inderscience Enterprises Ltd.