The composite materials of 0.5 Sm1.5Sr0.5NiO4, 0.5 CCTO and 0.75 Sm1.5Sr0.5NiO4, 0.25 CCTO mixtures were prepared through the conventional solid state reaction in an attempt to obtain good dielectric properties for practical applications. The structural properties were determined by powder X-ray diffraction and single phases were obtained for Sm1.5Sr0.5NiO4 and CaCu3Ti4O12 compounds. The dielectric studies analysed over a range of frequencies (100 KHz–10 MHz) and temperatures (30 to 200 °C) revealed a desired dielectric constant values with a low steady nature of dielectric loss factor. Through impedance spectroscopy, the attained dielectric behaviour was due to the highly insulating grain boundaries at lower frequencies and semiconducting grains at higher frequencies.