Dielectric properties of Mn_0.4Zn_0.6Fe₂O₄ ferrites synthesised by co-precipitation method have been investigated as a function of frequency (up to 30MHz) at different temperatures. Dispersion in dielectric constant has been observed between temperatures 450–500K. DC resistivity was found to increase up to 100 times greater than those for the samples prepared by the conventional ceramic methods. Resistivity variation with temperature is also reported in the present work. The particle size is calculated using Scherrer equation for Lorentzian peak, which comes out between 9 and 19nm. Possible mechanisms contributing to these processes have been discussed.