Abstract. Nanosized Nickel substituted Cobalt-Zinc ferrites with the formula Co0.5-xNixZn0.5Fe2O4 (where x = 0, 0.1, 0.2, 0.3) were chosen and prepared by co-precipitation method by decomposition of their respective metal chlorides and zinc sulphate heptahydrate. The heat treatment of the ground precursor powders at their respective decomposition temperature and beyond, results in the evolution of heat from the combustion of the residual chlorides and sulphate materials. This facilitates the reactions among the constituent metal ions and the formation of the desired oxide phase at low temperature. The average crystallite sizes were determined from X-ray pattern. The FTIR studies have been used to confirm the formation of metal oxide. The migration of Fe3+ ion from octahedral site to tetrahedral site decreases the electrical conductivity with increase in nickel concentration due to the charge libration and electron hoping together form the basis for the conduction mechanism.