Sodium modified PLZT, Pb-0.98(La1-x/3Nax)(0.02)(Zr0.53Ti0.47)(0.9950)O-3 (PLNZT) with x = 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, ceramics have been synthesized by spray drying technique. Rhombohedral phases of PLNZT ceramics were confirmed by XRD. Pellets prepared from the calcined powders were sintered at 1100degreesC. Micro-structural studies show the grains were spherical and homogeneous. Dielectric behaviour of these compounds has been studied as a function of temperature at 10 KHz frequency. Diffusivity of these compounds calculated from epsilon-T plots were found to lie between 1 and 2, which suggests that the compounds have diffuse phase transition (DPT). The dielectric constant (epsilon) as found to increase initially upto x = 1.5 and then to decrease with increasing Na-concentrations. (C) 2005 Springer Science + Business Media, Inc.