The single phase nano-crystalline lead-free Na 0.5 Bi 0.5 TiO 3 (NBT) synthesized using hydrothermal technique produces homogeneous crystalline powders. The structural phase purity of these ceramic powders was confirmed by using room temperature X-ray diffraction and it revealed that the structure stabilizes in rhombohedral (R3c) phase. The microstructure from scanning electron microscopy clearly showed the cubic-type feature in orders of 100-200nm with sharp face edges. The Curie temperature (T C ), dielectric constant (ϵ r ) and other electrical properties are strongly dependent on the particle sizes. The dielectric constant (ϵ r = 3100 at 100kHz) is high in comparison to reported NBT synthesized using solid state route (ϵ r = 2700 at 100kHz). Additionally, diffusive phase transition was clearly observed in nano NBT powders which supports its tendency towards more relaxor behavior and will be a pertinent candidate to improve the energy storage capacity. © 2019 Author(s).