Here we report the effect of vanadium doping on the dielectric and electrical properties of giant dielectric material CaCu 3 Ti 4 O 12 (CCTO), synthesized through conventional solid-state reaction process. Proper crystalline phase formation together with dopant induced lattice constant shrinkage was confirmed through X-ray diffraction studies. The X-ray photoelectron spectroscopic studies confirmed vanadium doping with V 4+ replacing Ti 4+ at its lattice site. The grain boundary resistivity was found to decrease monotonically with the increase of V doping percentages as revealed by impedance spectroscopic measurement and furthermore the grain size was found to follow the similar trend. The reduced grain boundary resistivity was found to be responsible for the overall variation of current density–electric field (J–E) characteristics.