NanocrystallineNixZn1-xFe2O4with x = 0.1 to 0.5mixed ferriteswere prepared by Sucrose process. The samples were characterized by high resolution TEM, XRD and IR spectroscopy. The dielectric behavior was studied in the frequency range 20 Hz to 1MHz. Dielectric constant shows dispersion in lower frequency region. XRD patterns confirmthe formation of spinel cubic structure. The IR spectra show two prominent absorption bands.