Abstract: A process for producing a nanographite dispersion in a fluid wherein the thermal conductivity of the dispersion is enhanced from the base fluid by more than 10% for a 1% graphite dispersion. A high purity graphite with high crystallinity and reduced surface damage and oxidation is selected as the starting material. The starting material is subjected to a process of wet media milling in the presence of dispersant and solvent fluid. The mill temperature is controlled to control and reduce surface damage to yield a nanographite with flake shape and controlled aspect ratio until a particle size average of 300 nm diameter and 50 nm is obtained. The process recycles a portion of the milled material to increase the ratio of small particle distribution to large particles in an intermediate product with small and large particle bi-modal distribution. The large particle distribution is removed by a separation process such as centrifugation or filtration.