Nanoparticles of barium dysprosium antimonate (Ba 2 DySbO 6 ), a complex double perovskite ceramic oxide, synthesized by a novel single-step auto ignition combustion process is presented for the first time. The phase purity was examined by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA) and Fourier transform infrared (FT-IR) spectroscopy. The surface and ultrafine morphology were examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The XRD studies shown that the as-prepared powder is phase pure Ba 2 DySbO 6 and has a complex cubic perovskite (A 2 BB′O 6 ) crystalline structure with lattice constant a=8.4376Å. The TEM image of the as-prepared powder reveals that the particle size is in the range 20–50nm. The nanocrystals of Ba 2 DySbO 6 synthesized by the combustion technique could be sintered to 97% of the theoretical density at a temperature of 1550°C for 3h. The dielectric constant (ɛ r ) was 17 and the loss factor (tanδ) was 5×10 −3 at 3MHz.