Barium stannate (BaSnO 3 ) particles were synthesized using a one-step ame spray pyrolysis (FSP) method. The fabricated ceramic powders were investigated in terms of the structural, morphological, and optical properties by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-Ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), zeta particle size analyzer, UVvisible spectroscopy (UV-vis) and photoluminescence spectroscopy (PL). The XRD results showed the structure of BaSnO 3 crystals have been obtained when the powders were exposed at high temperature, speci cally at 1200 °C. The synthesized particles in the submicron size in a range of 70-980 nm were produced. The optical band gap value of the synthesized crystals was calculated by means of re ectance spectra with the Kubelka-Munk method and found as 3.14 eV. When the powders excited at 375 nm, they exhibited emission bands in the visible and near-infrared region (NIR) of the electromagnetic spectrum.As far as we know, this is the rst time BaSnO 3 crystals have been synthesized using the FSP technique.In this study, the intensity-and decay time-based gas sensing properties of BaSnO 3 embedded in ethyl cellulose thin lms when exposed to the vapors of ethanol, acetone, and ammonia were also measured.